Automatic control of wearable display device based on external conditions

ABSTRACT

Embodiments of a wearable device can include a head-mounted display (HMD) which can be configured to display virtual content. While the user is interacting with visual or audible virtual content, the user of the wearable may encounter a triggering event such as, for example, an emergency condition or an unsafe condition, detecting one or more triggering objects in an environment, or determining characteristics of the user&#39;s environment (e.g., home or office). Embodiments of the wearable device can automatically detect the triggering event and automatically control the HMD to deemphasize, block, or stop displaying the virtual content. The HMD may include a button that can be actuated by the user to manually deemphasize, block, or stop displaying the virtual content.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/816,875, filed on Nov. 17, 2017, entitled “AUTOMATIC CONTROL OFWEARABLE DISPLAY DEVICE BASED ON EXTERNAL CONDITIONS,” which claims thebenefit of priority under 35 U.S.C. § 119(e) to U.S. ProvisionalApplication No. 62/440,099, filed on Dec. 29, 2016, entitled “MANUAL ORAUTOMATIC CONTROL OF WEARABLE DISPLAY DEVICE BASED ON EXTERNALCONDITIONS,” the disclosure of which is hereby incorporated by referenceherein in its entirety.

FIELD

The present disclosure relates to mixed reality imaging andvisualization systems and more particularly to automatic controls ofmixed reality imaging and visualization system based on externalconditions.

BACKGROUND

Modern computing and display technologies have facilitated thedevelopment of systems for so called “virtual reality”, “augmentedreality”, or “mixed reality” experiences, wherein digitally reproducedimages or portions thereof are presented to a user in a manner whereinthey seem to be, or may be perceived as, real. A virtual reality, or“VR”, scenario typically involves presentation of digital or virtualimage information without transparency to other actual real-world visualinput; an augmented reality, or “AR”, scenario typically involvespresentation of digital or virtual image information as an augmentationto visualization of the actual world around the user; a mixed reality,or “MR”, related to merging real and virtual worlds to produce newenvironments where physical and virtual objects co-exist and interact inreal time. As it turns out, the human visual perception system is verycomplex, and producing a VR, AR, or MR technology that facilitates acomfortable, natural-feeling, rich presentation of virtual imageelements amongst other virtual or real-world imagery elements ischallenging. Systems and methods disclosed herein address variouschallenges related to VR, AR and MR technology.

SUMMARY

Embodiments of a wearable device can include a head-mounted display(HMD) which can be configured to display virtual content. While the useris interacting with visual or audible virtual content, the user of thewearable device may encounter a triggering event such as, for example,an emergency condition or an unsafe condition, detecting one or moretriggering objects in an environment, or detecting that a user hasentered into a particular environment (e.g., home or office).Embodiments of the wearable device can automatically detect thetriggering event and automatically control the HMD to deemphasize,block, or stop displaying the virtual content. The HMD may include abutton that can be actuated by the user to manually deemphasize, block,or stop displaying the virtual content. In certain implementations, thewearable device can resume or restore the virtual content in response todetection of a termination condition.

Details of one or more implementations of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Neitherthis summary nor the following detailed description purports to defineor limit the scope of the inventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts an illustration of a mixed reality scenario with certainvirtual reality objects, and certain physical objects viewed by aperson.

FIG. 1B illustrates a field of view and a field of regard for a wearerof a wearable display system.

FIG. 2 schematically illustrates an example of a wearable system.

FIG. 3 schematically illustrates aspects of an approach for simulatingthree-dimensional imagery using multiple depth planes.

FIG. 4 schematically illustrates an example of a waveguide stack foroutputting image information to a user.

FIG. 5 shows example exit beams that may be outputted by a waveguide.

FIG. 6 is a schematic diagram showing an optical system including awaveguide apparatus, an optical coupler subsystem to optically couplelight to or from the waveguide apparatus, and a control subsystem, usedin the generation of a multi-focal volumetric display, image, or lightfield.

FIG. 7 is a block diagram of an example of a wearable system.

FIG. 8 is a process flow diagram of an example of a method of renderingvirtual content in relation to recognized objects.

FIG. 9 is a block diagram of another example of a wearable system.

FIG. 10 shows a schematic view of an example of various components of anwearable system comprising environmental sensors.

FIGS. 11A and 11B illustrate an example of muting a head-mounted display(HMD) in a surgical context.

FIG. 11C illustrates an example of muting an HMD in an industrialcontext.

FIG. 11D illustrates an example of muting an HMD in an educationalcontext.

FIG. 11E illustrates an example of muting an HMD in a shopping context.

FIG. 11F illustrates an example of selectively blocking virtual contentin a work environment.

FIG. 11G illustrates an example of selectively blocking virtual contentin a break room environment.

FIGS. 12A, 12B, and 12C illustrate examples of muting virtual contentpresented by an HMD based on a triggering event.

FIG. 12D illustrates an example of muting virtual content upon detectinga change in a user's environment.

FIGS. 13A and 13B illustrate example processes of muting an augmentedreality display device based on a triggering event.

FIG. 13C illustrates an example flowchart for selectively blockingvirtual content in an environment.

FIG. 14A illustrates an alert message that can be displayed by an HMD inresponse to manual actuation of a reality button.

FIG. 14B is a flowchart that shows an example process for manuallyactivating a mute mode of operation of an HMD.

Throughout the drawings, reference numbers may be re-used to indicatecorrespondence between referenced elements. The drawings are provided toillustrate example embodiments described herein and are not intended tolimit the scope of the disclosure.

DETAILED DESCRIPTION

Overview

The display system of a wearable device can be configured to presentvirtual content in an AR/VR/MR environment. The virtual content caninclude visual and/or audible content. While using a head-mounteddisplay device (HMD), the user may encounter situations in which it maybe desirable for some or all of the virtual content to be deemphasizedor not provided at all. For example, the user may encounter an emergencycondition or an unsafe condition during which the user's full attentionshould be on the actual, physical reality without potential distractionfrom the virtual content. In such conditions, presentation of virtualcontent to the user may cause perceptual confusion as the user tries toprocess both the actual physical content of the real world as well asthe virtual content provided by the HMD. Accordingly, as describedfurther below, embodiments of the HMD may provide manual or automaticcontrol of the HMD in cases where it may be desirable to deemphasize orstop displaying the virtual content.

Furthermore, while the wearable device can present a rich amount ofinformation to a user, in some situations, it may be difficult for theuser to sift through virtual content to identify the content that a useris interested in interacting with. Advantageously, in some embodiments,the wearable device can automatically detect a location of the user andselectively block (or selectively allow) virtual content based on thelocation, and thus the wearable device can present virtual content withhigher relevance to the user and appropriate to the user's environment(e.g., location) such as whether the user is at home or at work. Forexample, the wearable device can present a variety of virtual contentrelating to video games, scheduled conference calls, or work emails. Ifthe user is in an office, the user may wish to view the work relatedvirtual content, such as, e.g., conference calls and emails but blockvirtual content related to video games so that the user may focus onwork.

In certain implementations, the wearable device can automatically detecta change in a user's location based on image data acquired by anoutward-facing imaging system (alone or in combination with a locationsensor). The wearable device can automatically apply a settingappropriate to the current location in response to a detection that theuser has moved from one environment to another. In certainimplementations, the wearable system can mute virtual content based onthe user's environment (also referred to as scenes). For example, aliving room in a home and a mall may both be considered as anentertainment scene and thus similar virtual content may be blocked (orallowed) in both environments. Virtual content may also be blocked (orallowed) based on whether content having similar characteristics isblocked (or allowed). For example, a user may choose to block a socialnetworking application in an office environment (or may choose to allowonly work-related content). Based on this configuration provided by theuser, the wearable system can automatically block a video game for theoffice environment, because both the video game and the socialnetworking application have recreational characteristics.

Although the examples are described with reference to muting virtualcontent, similar techniques can also be applied for muting one or morecomponents of the wearable system. For example, the wearable system canmute the inward-facing imaging system in response to an emergencysituation (e.g., a fire) to preserves system's hardware resources.Further, although certain examples are described as selectively blockingcertain virtual content in certain environments, this is forillustration, and the mixed reality device could additionally oralternatively selectively allow different virtual content, to achievesubstantially the same results as blocking.

Examples of 3D Display

A wearable system (also referred to herein as an augmented reality (AR)system) can be configured to present 2D or 3D virtual images to a user.The images may be still images, frames of a video, or a video, incombination or the like. At least a portion of the wearable system canbe implemented on a wearable device that can present a VR, AR, or MRenvironment, alone or in combination, for user interaction. The wearabledevice can be used interchangeably as an AR device (ARD). Further, forthe purpose of the present disclosure, the term “AR” is usedinterchangeably with the term “MR”.

FIG. 1A depicts an illustration of a mixed reality scenario with certainvirtual reality objects, and certain physical objects viewed by aperson. In FIG. 1A, an MR scene 100 is depicted wherein a user of an MRtechnology sees a real-world park-like setting 110 featuring people,trees, buildings in the background, and a concrete platform 120. Inaddition to these items, the user of the MR technology also perceivesthat he “sees” a robot statue 130 standing upon the real-world platform120, and a cartoon-like avatar character 140 flying by which seems to bea personification of a bumble bee, even though these elements do notexist in the real world.

In order for the 3D display to produce a true sensation of depth, andmore specifically, a simulated sensation of surface depth, it may bedesirable for each point in the display's visual field to generate anaccommodative response corresponding to its virtual depth. If theaccommodative response to a display point does not correspond to thevirtual depth of that point, as determined by the binocular depth cuesof convergence and stereopsis, the human eye may experience anaccommodation conflict, resulting in unstable imaging, harmful eyestrain, headaches, and, in the absence of accommodation information,almost a complete lack of surface depth.

FIG. 1B illustrates a person's field of view (FOV) and field of regard(FOR). The FOV comprises a portion of an environment of the user that isperceived at a given time by the user. This field of view can change asthe person moves about, moves their head, or moves their eyes or gaze.

The FOR comprises a portion of the environment around the user that iscapable of being perceived by the user via the wearable system.Accordingly, for a user wearing a head-mounted display device, the fieldof regard may include substantially all of the 4π steradian solid anglesurrounding the wearer, because the wearer can move his or her body,head, or eyes to perceive substantially any direction in space. In othercontexts, the user's movements may be more constricted, and accordinglythe user's field of regard may subtend a smaller solid angle. FIG. 1Bshows such a field of view 155 including central and peripheral regions.The central field of view will provide a person a corresponding view ofobjects in a central region of the environmental view. Similarly, theperipheral field of view will provide a person a corresponding view ofobjects in a peripheral region of the environmental view. In this case,what is considered central and what is considered peripheral is afunction of which direction the person is looking, and hence their fieldof view. The field of view 155 may include objects 121, 122. In thisexample, the central field of view 145 includes the object 121, whilethe other object 122 is in the peripheral field of view.

The field of view (FOV) 155 can contain multiple objects (e.g. objects121, 122). The field of view 155 can depend on the size or opticalcharacteristics of the AR system, for example, clear aperture size ofthe transparent window or lens of the head mounted display through whichlight passes from the real world in front of the user to the user'seyes. In some embodiments, as the user's 210 pose changes (e.g., headpose, body pose, and/or eye pose), the field of view 155 cancorrespondingly change, and the objects within the field of view 155 mayalso change. As described herein, the wearable system may includesensors such as cameras that monitor or image objects in the field ofregard 165 as well as objects in the field of view 155. In some suchembodiments, the wearable system may alert the user of unnoticed objectsor events occurring in the user's field of view 155 and/or occurringoutside the user's field of view but within the field of regard 165. Insome embodiments, the wearable system can also distinguish between whata user 210 is or is not directing attention to.

The objects in the FOV or the FOR may be virtual or physical objects.The virtual objects may include, for example, operating system objectssuch as e.g., a terminal for inputting commands, a file manager foraccessing files or directories, an icon, a menu, an application foraudio or video streaming, a notification from an operating system, andso on. The virtual objects may also include objects in an applicationsuch as e.g., avatars, virtual objects in games, graphics or images,etc. Some virtual objects can be both an operating system object and anobject in an application. The wearable system can add virtual elementsto the existing physical objects viewed through the transparent opticsof the head mounted display, thereby permitting user interaction withthe physical objects. For example, the wearable system may add a virtualmenu associated with a medical monitor in the room, where the virtualmenu may give the user the option to turn on or adjust medical imagingequipment or dosing controls. Accordingly, the head-mounted display maypresent additional virtual image content to the wearer in addition tothe object in the environment of the user.

FIG. 1B also shows the field of regard (FOR) 165, which comprises aportion of the environment around a person 210 that is capable of beingperceived by the person 210, for example, by turning their head orredirecting their gaze. The center portion of the field of view 155 of aperson's 210 eyes may be referred to as the central field of view 145.The region within the field of view 155 but outside the central field ofview 145 may be referred to as the peripheral field of view. In FIG. 1B,the field of regard 165 can contain a group of objects (e.g., objects121, 122, 127) which can be perceived by the user wearing the wearablesystem.

In some embodiments, objects 129 may be outside the user's visual FORbut may nonetheless potentially be perceived by a sensor (e.g., acamera) on a wearable device (depending on their location and field ofview) and information associated with the object 129 displayed for theuser 210 or otherwise used by the wearable device. For example, theobjects 129 may be behind a wall in a user's environment so that theobjects 129 are not visually perceivable by the user. However, thewearable device may include sensors (such as radio frequency, Bluetooth,wireless, or other types of sensors) that can communicate with theobjects 129.

Examples of a Display System

VR, AR, and MR experiences can be provided by display systems havingdisplays in which images corresponding to a plurality of depth planesare provided to a viewer. The images may be different for each depthplane (e.g., provide slightly different presentations of a scene orobject) and may be separately focused by the viewer's eyes, therebyhelping to provide the user with depth cues based on the accommodationof the eye required to bring into focus different image features for thescene located on different depth plane or based on observing differentimage features on different depth planes being out of focus. Asdiscussed elsewhere herein, such depth cues provide credible perceptionsof depth.

FIG. 2 illustrates an example of wearable system 200 which can beconfigured to provide an AR/VR/MR scene. The wearable system 200 canalso be referred to as the AR system 200. The wearable system 200includes a display 220, and various mechanical and electronic modulesand systems to support the functioning of display 220. The display 220may be coupled to a frame 230, which is wearable by a user, wearer, orviewer 210. The display 220 can be positioned in front of the eyes ofthe user 210. The display 220 can present AR/VR/MR content to a user.The display 220 can comprise a head mounted display (HMD) that is wornon the head of the user. In some embodiments, a speaker 240 is coupledto the frame 230 and positioned adjacent the ear canal of the user (insome embodiments, another speaker, not shown, is positioned adjacent theother ear canal of the user to provide for stereo/shapeable soundcontrol). The wearable system 200 can include an audio sensor 232 (e.g.,a microphone) for detecting an audio stream from the environment andcapture ambient sound. In some embodiments, one or more other audiosensors, not shown, are positioned to provide stereo sound reception.Stereo sound reception can be used to determine the location of a soundsource. The wearable system 200 can perform voice or speech recognitionon the audio stream.

The wearable system 200 can include an outward-facing imaging system 464(shown in FIG. 4 ) which observes the world in the environment aroundthe user. The wearable system 200 can also include an inward-facingimaging system 462 (shown in FIG. 4 ) which can track the eye movementsof the user. The inward-facing imaging system may track either one eye'smovements or both eyes' movements. The inward-facing imaging system 462may be attached to the frame 230 and may be in electrical communicationwith the processing modules 260 or 270, which may process imageinformation acquired by the inward-facing imaging system to determine,e.g., the pupil diameters or orientations of the eyes, eye movements oreye pose of the user 210.

As an example, the wearable system 200 can use the outward-facingimaging system 464 or the inward-facing imaging system 462 to acquireimages of a pose of the user. The images may be still images, frames ofa video, or a video.

The wearable system 200 can include a user-selectable reality button 263that can be used to attenuate the visual or audible content presented bythe wearable system 200 to the user. When the reality button 263 isactuated, the visual or audible virtual content is reduced (compared tonormal display conditions) so that the user perceives more of theactual, physical reality occurring in the user's environment. Thereality button 263 may be touch or pressure sensitive and may bedisposed on the frame 230 of the wearable system 200 or on a batterypower pack (e.g., worn near the user's waist, for example, on a beltclip). The reality button 263 will be further described below withreference to FIGS. 14A and 14B.

The display 220 can be operatively coupled 250, such as by a wired leador wireless connectivity, to a local data processing module 260 whichmay be mounted in a variety of configurations, such as fixedly attachedto the frame 230, fixedly attached to a helmet or hat worn by the user,embedded in headphones, or otherwise removably attached to the user 210(e.g., in a backpack-style configuration, in a belt-coupling styleconfiguration).

The local processing and data module 260 may comprise a hardwareprocessor, as well as digital memory, such as non-volatile memory (e.g.,flash memory), both of which may be utilized to assist in theprocessing, caching, and storage of data. The data may include data a)captured from sensors (which may be, e.g., operatively coupled to theframe 230 or otherwise attached to the user 210), such as image capturedevices (e.g., cameras in the inward-facing imaging system or theoutward-facing imaging system), audio sensors (e.g., microphones),inertial measurement units (IMUs), accelerometers, compasses, globalpositioning system (GPS) units, radio devices, or gyroscopes; or b)acquired or processed using remote processing module 270 or remote datarepository 280, possibly for passage to the display 220 after suchprocessing or retrieval. The local processing and data module 260 may beoperatively coupled by communication links 262 or 264, such as via wiredor wireless communication links, to the remote processing module 270 orremote data repository 280 such that these remote modules are availableas resources to the local processing and data module 260. In addition,remote processing module 280 and remote data repository 280 may beoperatively coupled to each other.

In some embodiments, the remote processing module 270 may comprise oneor more processors configured to analyze and process data or imageinformation. In some embodiments, the remote data repository 280 maycomprise a digital data storage facility, which may be available throughthe internet or other networking configuration in a “cloud” resourceconfiguration. In some embodiments, all data is stored and allcomputations are performed in the local processing and data module,allowing fully autonomous use from a remote module.

Example Environmental Sensors

The environmental sensors 267 may be configured to detect objects,stimuli, people, animals, locations, or other aspects of the worldaround the user. As further described with references to FIGS. 11A-11C,the information acquired by the environment sensors 267 may be used todetermine one or more triggering event which can cause the wearabledevice to mute audio or virtual perceptions. The environmental sensorsmay include image capture devices (e.g., cameras, inward-facing imagingsystem, outward-facing imaging system, etc.), microphones, inertialmeasurement units (IMUs), accelerometers, compasses, global positioningsystem (GPS) units, radio devices, gyroscopes, altimeters, barometers,chemical sensors, humidity sensors, temperature sensors, externalmicrophones, light sensors (e.g., light meters), timing devices (e.g.,clocks or calendars), or any combination or subcombination thereof. Insome embodiments, the environmental sensors may also include a varietyof physiological sensors. These sensors can measure or estimate theuser's physiological parameters such as heart rate, respiratory rate,galvanic skin response, blood pressure, encephalographic state, and soon. Environmental sensors may further include emissions devicesconfigured to receive signals such as laser, visible light, invisiblewavelengths of light, or sound (e.g., audible sound, ultrasound, orother frequencies). In some embodiments, one or more environmentalsensors (e.g., cameras or light sensors) may be configured to measurethe ambient light (e.g., luminance) of the environment (e.g., to capturethe lighting conditions of the environment). Physical contact sensors,such as strain gauges, curb feelers, or the like, may also be includedas environmental sensors. Additional details on the environmentalsensors 267 are further described with reference to FIG. 10 .

The local processing and data module 260 may be operatively coupled bycommunication links 262 and/or 264, such as via wired or wirelesscommunication links, to the remote processing module 270 and/or remotedata repository 280 such that these remote modules are available asresources to the local processing and data module 260. In addition,remote processing module 262 and remote data repository 264 may beoperatively coupled to each other.

The wearable system 200 may further be configured to receive otherenvironmental inputs, such as global positioning satellite (GPS)location data, weather data, date and time, or other availableenvironmental data which may be received from the internet, satellitecommunication, or other suitable wired or wireless data communicationmethod. The processing module 260 may be configured to access furtherinformation characterizing a location of the user, such as pollen count,demographics, air pollution, environmental toxins, information fromsmart thermostats, lifestyle statistics, or proximity to other users,buildings, or a healthcare provider. In some embodiments, informationcharacterizing the location may be accessed using cloud-based or otherremote databases. The local processing module 270 may be configured toobtain such data and/or to further analyze data from any one orcombinations of the environmental sensors.

Examples of a 3D Light Field Display

The human visual system is complicated and providing a realisticperception of depth is challenging. Without being limited by theory, itis believed that viewers of an object may perceive the object as beingthree-dimensional due to a combination of vergence and accommodation.Vergence movements (e.g., rotational movements of the pupils toward oraway from each other to converge the lines of sight of the eyes tofixate upon an object) of the two eyes relative to each other areclosely associated with focusing (or “accommodation”) of the lenses ofthe eyes. Under normal conditions, changing the focus of the lenses ofthe eyes, or accommodating the eyes, to change focus from one object toanother object at a different distance will automatically cause amatching change in vergence to the same distance, under a relationshipknown as the “accommodation-vergence reflex.” Likewise, a change invergence will trigger a matching change in accommodation, under normalconditions. Display systems that provide a better match betweenaccommodation and vergence may form more realistic or comfortablesimulations of three-dimensional imagery.

FIG. 3 illustrates aspects of an approach for simulating athree-dimensional imagery using multiple depth planes. With reference toFIG. 3 , objects at various distances from eyes 302 and 304 on thez-axis are accommodated by the eyes 302 and 304 so that those objectsare in focus. The eyes 302 and 304 assume particular accommodated statesto bring into focus objects at different distances along the z-axis.Consequently, a particular accommodated state may be said to beassociated with a particular one of depth planes 306, which has anassociated focal distance, such that objects or parts of objects in aparticular depth plane are in focus when the eye is in the accommodatedstate for that depth plane. In some embodiments, three-dimensionalimagery may be simulated by providing different presentations of animage for each of the eyes 302 and 304, and also by providing differentpresentations of the image corresponding to each of the depth planes.While shown as being separate for clarity of illustration, it will beappreciated that the fields of view of the eyes 302 and 304 may overlap,for example, as distance along the z-axis increases. In addition, whileshown as flat for the ease of illustration, it will be appreciated thatthe contours of a depth plane may be curved in physical space, such thatall features in a depth plane are in focus with the eye in a particularaccommodated state. Without being limited by theory, it is believed thatthe human eye typically can interpret a finite number of depth planes toprovide depth perception. Consequently, a highly believable simulationof perceived depth may be achieved by providing, to the eye, differentpresentations of an image corresponding to each of these limited numberof depth planes.

Waveguide Stack Assembly

FIG. 4 illustrates an example of a waveguide stack for outputting imageinformation to a user. A wearable system 400 includes a stack ofwaveguides, or stacked waveguide assembly 480 that may be utilized toprovide three-dimensional perception to the eye/brain using a pluralityof waveguides 432 b, 434 b, 436 b, 438 b, 4400 b. In some embodiments,the wearable system 400 may correspond to wearable system 200 of FIG.2A, with FIG. 4 schematically showing some parts of that wearable system200 in greater detail. For example, in some embodiments, the waveguideassembly 480 may be integrated into the display 220 of FIG. 2A.

With continued reference to FIG. 4 , the waveguide assembly 480 may alsoinclude a plurality of features 458, 456, 454, 452 between thewaveguides. In some embodiments, the features 458, 456, 454, 452 may belenses. In other embodiments, the features 458, 456, 454, 452 may not belenses. Rather, they may simply be spacers (e.g., cladding layers orstructures for forming air gaps).

The waveguides 432 b, 434 b, 436 b, 438 b, 440 b or the plurality oflenses 458, 456, 454, 452 may be configured to send image information tothe eye with various levels of wavefront curvature or light raydivergence. Each waveguide level may be associated with a particulardepth plane and may be configured to output image informationcorresponding to that depth plane. Image injection devices 420, 422,424, 426, 428 may be utilized to inject image information into thewaveguides 440 b, 438 b, 436 b, 434 b, 432 b, each of which may beconfigured to distribute incoming light across each respectivewaveguide, for output toward the eye 410. Light exits an output surfaceof the image injection devices 420, 422, 424, 426, 428 and is injectedinto a corresponding input edge of the waveguides 440 b, 438 b, 436 b,434 b, 432 b. In some embodiments, a single beam of light (e.g., acollimated beam) may be injected into each waveguide to output an entirefield of cloned collimated beams that are directed toward the eye 410 atparticular angles (and amounts of divergence) corresponding to the depthplane associated with a particular waveguide.

In some embodiments, the image injection devices 420, 422, 424, 426, 428are discrete displays that each produce image information for injectioninto a corresponding waveguide 440 b, 438 b, 436 b, 434 b, 432 b,respectively. In some other embodiments, the image injection devices420, 422, 424, 426, 428 are the output ends of a single multiplexeddisplay which may, e.g., pipe image information via one or more opticalconduits (such as fiber optic cables) to each of the image injectiondevices 420, 422, 424, 426, 428.

A controller 460 controls the operation of the stacked waveguideassembly 480 and the image injection devices 420, 422, 424, 426, 428.The controller 460 includes programming (e.g., instructions in anon-transitory computer-readable medium) that regulates the timing andprovision of image information to the waveguides 440 b, 438 b, 436 b,434 b, 432 b. In some embodiments, the controller 460 may be a singleintegral device, or a distributed system connected by wired or wirelesscommunication channels. The controller 460 may be part of the processingmodules 260 or 270 (illustrated in FIG. 2A) in some embodiments.

The waveguides 440 b, 438 b, 436 b, 434 b, 432 b may be configured topropagate light within each respective waveguide by total internalreflection (TIR). The waveguides 440 b, 438 b, 436 b, 434 b, 432 b mayeach be planar or have another shape (e.g., curved), with major top andbottom surfaces and edges extending between those major top and bottomsurfaces. In the illustrated configuration, the waveguides 440 b, 438 b,436 b, 434 b, 432 b may each include light extracting optical elements440 a, 438 a, 436 a, 434 a, 432 a that are configured to extract lightout of a waveguide by redirecting the light, propagating within eachrespective waveguide, out of the waveguide to output image informationto the eye 410. Extracted light may also be referred to as outcoupledlight, and light extracting optical elements may also be referred to asoutcoupling optical elements. An extracted beam of light is outputted bythe waveguide at locations at which the light propagating in thewaveguide strikes a light redirecting element. The light extractingoptical elements (440 a, 438 a, 436 a, 434 a, 432 a) may, for example,be reflective or diffractive optical features. While illustrateddisposed at the bottom major surfaces of the waveguides 440 b, 438 b,436 b, 434 b, 432 b for ease of description and drawing clarity, in someembodiments, the light extracting optical elements 440 a, 438 a, 436 a,434 a, 432 a may be disposed at the top or bottom major surfaces, or maybe disposed directly in the volume of the waveguides 440 b, 438 b, 436b, 434 b, 432 b. In some embodiments, the light extracting opticalelements 440 a, 438 a, 436 a, 434 a, 432 a may be formed in a layer ofmaterial that is attached to a transparent substrate to form thewaveguides 440 b, 438 b, 436 b, 434 b, 432 b. In some other embodiments,the waveguides 440 b, 438 b, 436 b, 434 b, 432 b may be a monolithicpiece of material and the light extracting optical elements 440 a, 438a, 436 a, 434 a, 432 a may be formed on a surface or in the interior ofthat piece of material.

With continued reference to FIG. 4 , as discussed herein, each waveguide440 b, 438 b, 436 b, 434 b, 432 b is configured to output light to forman image corresponding to a particular depth plane. For example, thewaveguide 432 b nearest the eye may be configured to deliver collimatedlight, as injected into such waveguide 432 b, to the eye 410. Thecollimated light may be representative of the optical infinity focalplane. The next waveguide up 434 b may be configured to send outcollimated light which passes through the first lens 452 (e.g., anegative lens) before it can reach the eye 410. First lens 452 may beconfigured to create a slight convex wavefront curvature so that theeye/brain interprets light coming from that next waveguide up 434 b ascoming from a first focal plane closer inward toward the eye 410 fromoptical infinity. Similarly, the third up waveguide 436 b passes itsoutput light through both the first lens 452 and second lens 454 beforereaching the eye 410. The combined optical power of the first and secondlenses 452 and 454 may be configured to create another incrementalamount of wavefront curvature so that the eye/brain interprets lightcoming from the third waveguide 436 b as coming from a second focalplane that is even closer inward toward the person from optical infinitythan was light from the next waveguide up 434 b.

The other waveguide layers (e.g., waveguides 438 b, 440 b) and lenses(e.g., lenses 456, 458) are similarly configured, with the highestwaveguide 440 b in the stack sending its output through all of thelenses between it and the eye for an aggregate focal powerrepresentative of the closest focal plane to the person. To compensatefor the stack of lenses 458, 456, 454, 452 when viewing/interpretinglight coming from the world 470 on the other side of the stackedwaveguide assembly 480, a compensating lens layer 430 may be disposed atthe top of the stack to compensate for the aggregate power of the lensstack 458, 456, 454, 452 below. Such a configuration provides as manyperceived focal planes as there are available waveguide/lens pairings.Both the light extracting optical elements of the waveguides and thefocusing aspects of the lenses may be static (e.g., not dynamic orelectro-active). In some alternative embodiments, either or both may bedynamic using electro-active features.

With continued reference to FIG. 4 , the light extracting opticalelements 440 a, 438 a, 436 a, 434 a, 432 a may be configured to bothredirect light out of their respective waveguides and to output thislight with the appropriate amount of divergence or collimation for aparticular depth plane associated with the waveguide. As a result,waveguides having different associated depth planes may have differentconfigurations of light extracting optical elements, which output lightwith a different amount of divergence depending on the associated depthplane. In some embodiments, as discussed herein, the light extractingoptical elements 440 a, 438 a, 436 a, 434 a, 432 a may be volumetric orsurface features, which may be configured to output light at specificangles. For example, the light extracting optical elements 440 a, 438 a,436 a, 434 a, 432 a may be volume holograms, surface holograms, ordiffraction gratings. Light extracting optical elements, such asdiffraction gratings, are described in U.S. Patent Publication No.2015/0178939, published Jun. 25, 2015, which is incorporated byreference herein in its entirety.

In some embodiments, the light extracting optical elements 440 a, 438 a,436 a, 434 a, 432 a are diffractive features that form a diffractionpattern, or “diffractive optical element” (also referred to herein as a“DOE”). Preferably, the DOE has a relatively low diffraction efficiencyso that only a portion of the light of the beam is deflected away towardthe eye 410 with each intersection of the DOE, while the rest continuesto move through a waveguide via total internal reflection. The lightcarrying the image information can thus be divided into a number ofrelated exit beams that exit the waveguide at a multiplicity oflocations and the result is a fairly uniform pattern of exit emissiontoward the eye 304 for this particular collimated beam bouncing aroundwithin a waveguide.

In some embodiments, one or more DOEs may be switchable between “on”state in which they actively diffract, and “off” state in which they donot significantly diffract. For instance, a switchable DOE may comprisea layer of polymer dispersed liquid crystal, in which microdropletscomprise a diffraction pattern in a host medium, and the refractiveindex of the microdroplets can be switched to substantially match therefractive index of the host material (in which case the pattern doesnot appreciably diffract incident light) or the microdroplet can beswitched to an index that does not match that of the host medium (inwhich case the pattern actively diffracts incident light).

In some embodiments, the number and distribution of depth planes ordepth of field may be varied dynamically based on the pupil sizes ororientations of the eyes of the viewer. Depth of field may changeinversely with a viewer's pupil size. As a result, as the sizes of thepupils of the viewer's eyes decrease, the depth of field increases suchthat one plane that is not discernible because the location of thatplane is beyond the depth of focus of the eye may become discernible andappear more in focus with reduction of pupil size and commensurate withthe increase in depth of field. Likewise, the number of spaced apartdepth planes used to present different images to the viewer may bedecreased with the decreased pupil size. For example, a viewer may notbe able to clearly perceive the details of both a first depth plane anda second depth plane at one pupil size without adjusting theaccommodation of the eye away from one depth plane and to the otherdepth plane. These two depth planes may, however, be sufficiently infocus at the same time to the user at another pupil size withoutchanging accommodation.

In some embodiments, the display system may vary the number ofwaveguides receiving image information based upon determinations ofpupil size or orientation, or upon receiving electrical signalsindicative of particular pupil size or orientation. For example, if theuser's eyes are unable to distinguish between two depth planesassociated with two waveguides, then the controller 460 (which may be anembodiment of the local processing and data module 260) can beconfigured or programmed to cease providing image information to one ofthese waveguides. Advantageously, this may reduce the processing burdenon the system, thereby increasing the responsiveness of the system. Inembodiments in which the DOEs for a waveguide are switchable between theon and off states, the DOEs may be switched to the off state when thewaveguide does receive image information.

In some embodiments, it may be desirable to have an exit beam meet thecondition of having a diameter that is less than the diameter of the eyeof a viewer. However, meeting this condition may be challenging in viewof the variability in size of the viewer's pupils. In some embodiments,this condition is met over a wide range of pupil sizes by varying thesize of the exit beam in response to determinations of the size of theviewer's pupil. For example, as the pupil size decreases, the size ofthe exit beam may also decrease. In some embodiments, the exit beam sizemay be varied using a variable aperture.

The wearable system 400 can include an outward-facing imaging system 464(e.g., a digital camera) that images a portion of the world 470. Thisportion of the world 470 may be referred to as the field of view (FOV)of a world camera and the imaging system 464 is sometimes referred to asan FOV camera. The FOV of the world camera may or may not be the same asthe FOV of a viewer 210 which encompasses a portion of the world 470 theviewer 210 perceives at a given time. For example, in some situations,the FOV of the world camera may be larger than the viewer 210 of theviewer 210 of the wearable system 400. The entire region available forviewing or imaging by a viewer may be referred to as the field of regard(FOR). The FOR may include 4π steradians of solid angle surrounding thewearable system 400 because the wearer can move his body, head, or eyesto perceive substantially any direction in space. In other contexts, thewearer's movements may be more constricted, and accordingly the wearer'sFOR may subtend a smaller solid angle. As described with reference toFIG. 1B, the user 210 may also have an FOV associated with the user'seyes when the user is using the HMD. In some embodiments, the FOVassociated with the user's eyes may be the same as the FOV of theimaging system 464. In other embodiments, the FOV associated with theuser's eyes is different from the FOV of the imaging system 464. Imagesobtained from the outward-facing imaging system 464 can be used to trackgestures made by the user (e.g., hand or finger gestures), detectobjects in the world 470 in front of the user, and so forth.

The wearable system 400 can include an audio sensor 232, e.g., amicrophone, to capture ambient sound. As described above, in someembodiments, one or more other audio sensors can be positioned toprovide stereo sound reception useful to the determination of locationof a speech source. The audio sensor 232 can comprise a directionalmicrophone, as another example, which can also provide such usefuldirectional information as to where the audio source is located.

The wearable system 400 can also include an inward-facing imaging system466 (e.g., a digital camera), which observes the movements of the user,such as the eye movements and the facial movements. The inward-facingimaging system 466 may be used to capture images of the eye 410 todetermine the size or orientation of the pupil of the eye 304. Theinward-facing imaging system 466 can be used to obtain images for use indetermining the direction the user is looking (e.g., eye pose) or forbiometric identification of the user (e.g., via iris identification). Insome embodiments, at least one camera may be utilized for each eye, toseparately determine the pupil size or eye pose of each eyeindependently, thereby allowing the presentation of image information toeach eye to be dynamically tailored to that eye. In some otherembodiments, the pupil diameter or orientation of only a single eye 410(e.g., using only a single camera per pair of eyes) is determined andassumed to be similar for both eyes of the user. The images obtained bythe inward-facing imaging system 466 may be analyzed to determine theuser's eye pose or mood, which can be used by the wearable system 400 todecide which audio or visual content should be presented to the user.The wearable system 400 may also determine head pose (e.g., headposition or head orientation) using sensors such as IMUs,accelerometers, gyroscopes, etc.

The wearable system 400 can include a user input device 466 by which theuser can input commands to the controller 460 to interact with thewearable system 400. For example, the user input device 466 can includea trackpad, a touchscreen, a joystick, a multiple degree-of-freedom(DOF) controller, a capacitive sensing device, a game controller, akeyboard, a mouse, a directional pad (D-pad), a wand, a haptic device, atotem (e.g., functioning as a virtual user input device), and so forth.A multi-DOF controller can sense user input in some or all possibletranslations (e.g., left/right, forward/backward, or up/down) orrotations (e.g., yaw, pitch, or roll) of the controller. A multi-DOFcontroller which supports the translation movements may be referred toas a 3DOF while a multi-DOF controller which supports the translationsand rotations may be referred to as 6DOF. In some cases, the user mayuse a finger (e.g., a thumb) to press or swipe on a touch-sensitiveinput device to provide input to the wearable system 400 (e.g., toprovide user input to a user interface provided by the wearable system400). The user input device 466 may be held by the user's hand duringthe use of the wearable system 400. The user input device 466 can be inwired or wireless communication with the wearable system 400.

FIG. 5 shows an example of exit beams outputted by a waveguide. Onewaveguide is illustrated, but it will be appreciated that otherwaveguides in the waveguide assembly 480 may function similarly, wherethe waveguide assembly 480 includes multiple waveguides. Light 520 isinjected into the waveguide 432 b at the input edge 432 c of thewaveguide 432 b and propagates within the waveguide 432 b by TIR. Atpoints where the light 520 impinges on the DOE 432 a, a portion of thelight exits the waveguide as exit beams 510. The exit beams 510 areillustrated as substantially parallel but they may also be redirected topropagate to the eye 410 at an angle (e.g., forming divergent exitbeams), depending on the depth plane associated with the waveguide 432b. It will be appreciated that substantially parallel exit beams may beindicative of a waveguide with light extracting optical elements thatoutcouple light to form images that appear to be set on a depth plane ata large distance (e.g., optical infinity) from the eye 410. Otherwaveguides or other sets of light extracting optical elements may outputan exit beam pattern that is more divergent, which would require the eye410 to accommodate to a closer distance to bring it into focus on theretina and would be interpreted by the brain as light from a distancecloser to the eye 410 than optical infinity.

FIG. 6 is a schematic diagram showing an optical system including awaveguide apparatus, an optical coupler subsystem to optically couplelight to or from the waveguide apparatus, and a control subsystem, usedin the generation of a multi-focal volumetric display, image, or lightfield. The optical system can include a waveguide apparatus, an opticalcoupler subsystem to optically couple light to or from the waveguideapparatus, and a control subsystem. The optical system can be used togenerate a multi-focal volumetric, image, or light field. The opticalsystem can include one or more primary planar waveguides 632 a (only oneis shown in FIG. 6 ) and one or more DOEs 632 b associated with each ofat least some of the primary waveguides 632 a. The planar waveguides 632b can be similar to the waveguides 432 b, 434 b, 436 b, 438 b, 440 bdiscussed with reference to FIG. 4 . The optical system may employ adistribution waveguide apparatus to relay light along a first axis(vertical or Y-axis in view of FIG. 6 ), and expand the light'seffective exit pupil along the first axis (e.g., Y-axis). Thedistribution waveguide apparatus may, for example, include adistribution planar waveguide 622 b and at least one DOE 622 a(illustrated by double dash-dot line) associated with the distributionplanar waveguide 622 b. The distribution planar waveguide 622 b may besimilar or identical in at least some respects to the primary planarwaveguide 632 b, having a different orientation therefrom. Likewise, atleast one DOE 622 a may be similar to or identical in at least somerespects to the DOE 632 a. For example, the distribution planarwaveguide 622 b or DOE 622 a may be comprised of the same materials asthe primary planar waveguide 632 b or DOE 632 a, respectively.Embodiments of the optical display system 600 shown in FIG. 6 can beintegrated into the wearable system 200 shown in FIG. 2A.

The relayed and exit-pupil expanded light may be optically coupled fromthe distribution waveguide apparatus into the one or more primary planarwaveguides 632 b. The primary planar waveguide 632 b can relay lightalong a second axis, preferably orthogonal to first axis (e.g.,horizontal or X-axis in view of FIG. 6 ). Notably, the second axis canbe a non-orthogonal axis to the first axis. The primary planar waveguide632 b expands the light's effective exit pupil along that second axis(e.g., X-axis). For example, the distribution planar waveguide 622 b canrelay and expand light along the vertical or Y-axis, and pass that lightto the primary planar waveguide 632 b which can relay and expand lightalong the horizontal or X-axis.

The optical system may include one or more sources of colored light(e.g., red, green, and blue laser light) 610 which may be opticallycoupled into a proximal end of a single mode optical fiber 640. A distalend of the optical fiber 640 may be threaded or received through ahollow tube 642 of piezoelectric material. The distal end protrudes fromthe tube 642 as fixed-free flexible cantilever 644. The piezoelectrictube 642 can be associated with four quadrant electrodes (notillustrated). The electrodes may, for example, be plated on the outside,outer surface or outer periphery or diameter of the tube 642. A coreelectrode (not illustrated) may also be located in a core, center, innerperiphery or inner diameter of the tube 642.

Drive electronics 650, for example electrically coupled via wires 660,drive opposing pairs of electrodes to bend the piezoelectric tube 642 intwo axes independently. The protruding distal tip of the optical fiber644 has mechanical modes of resonance. The frequencies of resonance candepend upon a diameter, length, and material properties of the opticalfiber 644. By vibrating the piezoelectric tube 642 near a first mode ofmechanical resonance of the fiber cantilever 644, the fiber cantilever644 can be caused to vibrate, and can sweep through large deflections.

By stimulating resonant vibration in two axes, the tip of the fibercantilever 644 is scanned biaxially in an area filling two-dimensional(2D) scan. By modulating an intensity of light source(s) 610 insynchrony with the scan of the fiber cantilever 644, light emerging fromthe fiber cantilever 644 can form an image. Descriptions of such a setup are provided in U.S. Patent Publication No. 2014/0003762, which isincorporated by reference herein in its entirety.

A component of an optical coupler subsystem can collimate the lightemerging from the scanning fiber cantilever 644. The collimated lightcan be reflected by mirrored surface 648 into the narrow distributionplanar waveguide 622 b which contains the at least one diffractiveoptical element (DOE) 622 a. The collimated light can propagatevertically (relative to the view of FIG. 6 ) along the distributionplanar waveguide 622 b by TIR, and in doing so repeatedly intersectswith the DOE 622 a. The DOE 622 a preferably has a low diffractionefficiency. This can cause a fraction (e.g., 10%) of the light to bediffracted toward an edge of the larger primary planar waveguide 632 bat each point of intersection with the DOE 622 a, and a fraction of thelight to continue on its original trajectory down the length of thedistribution planar waveguide 622 b via TIR.

At each point of intersection with the DOE 622 a, additional light canbe diffracted toward the entrance of the primary waveguide 632 b. Bydividing the incoming light into multiple outcoupled sets, the exitpupil of the light can be expanded vertically by the DOE 622 a in thedistribution planar waveguide 622 b. This vertically expanded lightcoupled out of distribution planar waveguide 622 b can enter the edge ofthe primary planar waveguide 632 b.

Light entering primary waveguide 632 b can propagate horizontally(relative to the view of FIG. 6 ) along the primary waveguide 632 b viaTIR. As the light intersects with DOE 632 a at multiple points as itpropagates horizontally along at least a portion of the length of theprimary waveguide 632 b via TIR. The DOE 632 a may advantageously bedesigned or configured to have a phase profile that is a summation of alinear diffraction pattern and a radially symmetric diffractive pattern,to produce both deflection and focusing of the light. The DOE 632 a mayadvantageously have a low diffraction efficiency (e.g., 10%), so thatonly a portion of the light of the beam is deflected toward the eye ofthe view with each intersection of the DOE 632 a while the rest of thelight continues to propagate through the primary waveguide 632 b viaTIR.

At each point of intersection between the propagating light and the DOE632 a, a fraction of the light is diffracted toward the adjacent face ofthe primary waveguide 632 b allowing the light to escape the TIR, andemerge from the face of the primary waveguide 632 b. In someembodiments, the radially symmetric diffraction pattern of the DOE 632 aadditionally imparts a focus level to the diffracted light, both shapingthe light wavefront (e.g., imparting a curvature) of the individual beamas well as steering the beam at an angle that matches the designed focuslevel.

Accordingly, these different pathways can cause the light to be coupledout of the primary planar waveguide 632 b by a multiplicity of DOEs 632a at different angles, focus levels, or yielding different fill patternsat the exit pupil. Different fill patterns at the exit pupil can bebeneficially used to create a light field display with multiple depthplanes. Each layer in the waveguide assembly or a set of layers (e.g., 3layers) in the stack may be employed to generate a respective color(e.g., red, blue, green). Thus, for example, a first set of threeadjacent layers may be employed to respectively produce red, blue andgreen light at a first focal depth. A second set of three adjacentlayers may be employed to respectively produce red, blue and green lightat a second focal depth. Multiple sets may be employed to generate afull 3D or 4D color image light field with various focal depths.

Other Components of the Wearable System

In many implementations, the wearable system may include othercomponents in addition or in alternative to the components of thewearable system described above. The wearable system may, for example,include one or more haptic devices or components. The haptic devices orcomponents may be operable to provide a tactile sensation to a user. Forexample, the haptic devices or components may provide a tactilesensation of pressure or texture when touching virtual content (e.g.,virtual objects, virtual tools, other virtual constructs). The tactilesensation may replicate a feel of a physical object which a virtualobject represents, or may replicate a feel of an imagined object orcharacter (e.g., a dragon) which the virtual content represents. In someimplementations, haptic devices or components may be worn by the user(e.g., a user wearable glove). In some implementations, haptic devicesor components may be held by the user.

The wearable system may, for example, include one or more physicalobjects which are manipulable by the user to allow input or interactionwith the wearable system. These physical objects may be referred toherein as totems. Some totems may take the form of inanimate objects,such as for example, a piece of metal or plastic, a wall, a surface oftable. In certain implementations, the totems may not actually have anyphysical input structures (e.g., keys, triggers, joystick, trackball,rocker switch). Instead, the totem may simply provide a physicalsurface, and the wearable system may render a user interface so as toappear to a user to be on one or more surfaces of the totem. Forexample, the wearable system may render an image of a computer keyboardand trackpad to appear to reside on one or more surfaces of a totem. Forexample, the wearable system may render a virtual computer keyboard andvirtual trackpad to appear on a surface of a thin rectangular plate ofaluminum which serves as a totem. The rectangular plate does not itselfhave any physical keys or trackpad or sensors. However, the wearablesystem may detect user manipulation or interaction or touches with therectangular plate as selections or inputs made via the virtual keyboardor virtual trackpad. The user input device 466 (shown in FIG. 4 ) may bean embodiment of a totem, which may include a trackpad, a touchpad, atrigger, a joystick, a trackball, a rocker or virtual switch, a mouse, akeyboard, a multi-degree-of-freedom controller, or another physicalinput device. A user may use the totem, alone or in combination withposes, to interact with the wearable system or other users.

Examples of haptic devices and totems usable with the wearable devices,HMD, and display systems of the present disclosure are described in U.S.Patent Publication No. 2015/0016777, which is incorporated by referenceherein in its entirety.

Example Wearable Systems, Environments, and Interfaces

A wearable system may employ various mapping related techniques in orderto achieve high depth of field in the rendered light fields. In mappingout the virtual world, it is advantageous to know all the features andpoints in the real world to accurately portray virtual objects inrelation to the real world. To this end, FOV images captured from usersof the wearable system can be added to a world model by including newpictures that convey information about various points and features ofthe real world. For example, the wearable system can collect a set ofmap points (such as 2D points or 3D points) and find new map points torender a more accurate version of the world model. The world model of afirst user can be communicated (e.g., over a network such as a cloudnetwork) to a second user so that the second user can experience theworld surrounding the first user.

FIG. 7 is a block diagram of an example of an MR environment 700. The MRenvironment 700 may be configured to receive input (e.g., visual input702 from the user's wearable system, stationary input 704 such as roomcameras, sensory input 706 from various sensors, gestures, totems, eyetracking, user input from the user input device 466 etc.) from one ormore user wearable systems (e.g., wearable system 200 or display system220) or stationary room systems (e.g., room cameras, etc.). The wearablesystems can use various sensors (e.g., accelerometers, gyroscopes,temperature sensors, movement sensors, depth sensors, GPS sensors,inward-facing imaging system, outward-facing imaging system, etc.) todetermine the location and various other attributes of the environmentof the user. This information may further be supplemented withinformation from stationary cameras in the room that may provide imagesor various cues from a different point of view. The image data acquiredby the cameras (such as the room cameras or the cameras of theoutward-facing imaging system) may be reduced to a set of mappingpoints.

One or more object recognizers 708 can crawl through the received data(e.g., the collection of points) and recognize or map points, tagimages, attach semantic information to objects with the help of a mapdatabase 710. The map database 710 may comprise various points collectedover time and their corresponding objects. The various devices and themap database can be connected to each other through a network (e.g.,LAN, WAN, etc.) to access the cloud.

Based on this information and collection of points in the map database,the object recognizers 708 a to 708 n may recognize objects in anenvironment. For example, the object recognizers can recognize faces,persons, windows, walls, user input devices, televisions, documents(e.g., travel tickets, driver's license, passport as described in thesecurity examples herein), other objects in the user's environment, etc.One or more object recognizers may be specialized for object withcertain characteristics. For example, the object recognizer 708 a may beused to recognizer faces, while another object recognizer may be usedrecognize documents.

The object recognitions may be performed using a variety of computervision techniques. For example, the wearable system can analyze theimages acquired by the outward-facing imaging system 464 (shown in FIG.4 ) to perform scene reconstruction, event detection, video tracking,object recognition (e.g., persons or documents), object pose estimation,facial recognition (e.g., from a person in the environment or an imageon a document), learning, indexing, motion estimation, or image analysis(e.g., identifying indicia within documents such as photos, signatures,identification information, travel information, etc.), and so forth. Oneor more computer vision algorithms may be used to perform these tasks.Non-limiting examples of computer vision algorithms include:Scale-invariant feature transform (SIFT), speeded up robust features(SURF), oriented FAST and rotated BRIEF (ORB), binary robust invariantscalable keypoints (BRISK), fast retina keypoint (FREAK), Viola-Jonesalgorithm, Eigenfaces approach, Lucas-Kanade algorithm, Horn-Schunkalgorithm, Mean-shift algorithm, visual simultaneous location andmapping (vSLAM) techniques, a sequential Bayesian estimator (e.g.,Kalman filter, extended Kalman filter, etc.), bundle adjustment,Adaptive thresholding (and other thresholding techniques), IterativeClosest Point (ICP), Semi Global Matching (SGM), Semi Global BlockMatching (SGBM), Feature Point Histograms, various machine learningalgorithms (such as e.g., support vector machine, k-nearest neighborsalgorithm, Naive Bayes, neural network (including convolutional or deepneural networks), or other supervised/unsupervised models, etc.), and soforth.

One or more object recognizers 708 can also implement various textrecognition algorithms to identify and extract the text from the images.Some example text recognition algorithms include: optical characterrecognition (OCR) algorithms, deep learning algorithms (such as deepneural networks), pattern matching algorithms, algorithms forpre-processing, etc.

The object recognitions can additionally or alternatively be performedby a variety of machine learning algorithms. Once trained, the machinelearning algorithm can be stored by the HMD. Some examples of machinelearning algorithms can include supervised or non-supervised machinelearning algorithms, including regression algorithms (such as, forexample, Ordinary Least Squares Regression), instance-based algorithms(such as, for example, Learning Vector Quantization), decision treealgorithms (such as, for example, classification and regression trees),Bayesian algorithms (such as, for example, Naive Bayes), clusteringalgorithms (such as, for example, k-means clustering), association rulelearning algorithms (such as, for example, a-priori algorithms),artificial neural network algorithms (such as, for example, Perceptron),deep learning algorithms (such as, for example, Deep Boltzmann Machine,or deep neural network), dimensionality reduction algorithms (such as,for example, Principal Component Analysis), ensemble algorithms (suchas, for example, Stacked Generalization), or other machine learningalgorithms. In some embodiments, individual models can be customized forindividual data sets. For example, the wearable device can generate orstore a base model. The base model may be used as a starting point togenerate additional models specific to a data type (e.g., a particularuser in the telepresence session), a data set (e.g., a set of additionalimages obtained of the user in the telepresence session), conditionalsituations, or other variations. In some embodiments, the wearable HMDcan be configured to utilize a plurality of techniques to generatemodels for analysis of the aggregated data. Other techniques may includeusing pre-defined thresholds or data values.

Based on this information and collection of points in the map database,the object recognizers 708 a to 708 n may recognize objects andsupplement objects with semantic information to give life to theobjects. For example, if the object recognizer recognizes a set ofpoints to be a door, the system may attach some semantic information(e.g., the door has a hinge and has a 90 degree movement about thehinge). If the object recognizer recognizes a set of points to be amirror, the system may attach semantic information that the mirror has areflective surface that can reflect images of objects in the room. Thesemantic information can include affordances of the objects as describedherein. For example, the semantic information may include a normal ofthe object. The system can assign a vector whose direction indicates thenormal of the object. In certain implementations, once an objectrecognizer 708 recognizes an environment (e.g., a leisure or workenvironment, a public or private environment, or a home environment,etc.) based on objects recognized from images of the user'ssurroundings, the wearable system can associate the recognizedenvironment to certain coordinates in the world map or GPS coordinates.For example, once the wearable system recognizes (e.g., via the objectrecognizer 708 or a user's response) that an environment is a livingroom in a user's home, the wearable system can automatically associatethe location of the environment with a GPS coordinate or with a locationin a world map. As a result, when a user enters the same location in thefuture, the wearable system can present/block virtual content based onthe living room environment. The wearable system can also create, aspart of the semantic information for the environment, a setting formuting the wearable device or for presenting tailored content for therecognized environment. Thus, when the user enters the same location inthe future, the wearable system can automatically present virtualcontent or mute the wearable device in accordance with the environment,without needing to re-recognize the type of the environment, which canimprove efficiency and reduce latency.

Over time the map database grows as the system (which may reside locallyor may be accessible through a wireless network) accumulates more datafrom the world. Once the objects are recognized, the information may betransmitted to one or more wearable systems. For example, the MRenvironment 700 may include information about a scene happening inCalifornia. The environment 700 may be transmitted to one or more usersin New York. Based on data received from an FOV camera and other inputs,the object recognizers and other software components can map the pointscollected from the various images, recognize objects etc., such that thescene may be accurately “passed over” to a second user, who may be in adifferent part of the world. The environment 700 may also use atopological map for localization purposes.

FIG. 8 is a process flow diagram of an example of a method 800 ofrendering virtual content in relation to recognized objects. The method800 describes how a virtual scene may be presented to a user of thewearable system. The user may be geographically remote from the scene.For example, the user may be in New York, but may want to view a scenethat is presently going on in California, or may want to go on a walkwith a friend who resides in California.

At block 810, the wearable system may receive input from the user andother users regarding the environment of the user. This may be achievedthrough various input devices, and knowledge already possessed in themap database. The user's FOV camera, sensors, GPS, eye tracking, etc.,convey information to the system at block 810. The system may determinesparse points based on this information at block 820. The sparse pointsmay be used in determining pose data (e.g., head pose, eye pose, bodypose, or hand gestures) that can be used in displaying and understandingthe orientation and position of various objects in the user'ssurroundings. The object recognizers 708 a-708 n may crawl through thesecollected points and recognize one or more objects using a map databaseat block 830. This information may then be conveyed to the user'sindividual wearable system at block 840, and the desired virtual scenemay be accordingly displayed to the user at block 850. For example, thedesired virtual scene (e.g., user in CA) may be displayed at theappropriate orientation, position, etc., in relation to the variousobjects and other surroundings of the user in New York.

FIG. 9 is a block diagram of another example of a wearable system. Inthis example, the wearable system 900 comprises a map 920, which mayinclude the map database 710 containing map data for the world. The mapmay partly reside locally on the wearable system, and may partly resideat networked storage locations accessible by wired or wireless network(e.g., in a cloud system). A pose process 910 may be executed on thewearable computing architecture (e.g., processing module 260 orcontroller 460) and utilize data from the map 920 to determine positionand orientation of the wearable computing hardware or user. Pose datamay be computed from data collected on the fly as the user isexperiencing the system and operating in the world. The data maycomprise images, data from sensors (such as inertial measurement units,which generally comprise accelerometer and gyroscope components) andsurface information pertinent to objects in the real or virtualenvironment.

A sparse point representation may be the output of a simultaneouslocalization and mapping (e.g., SLAM or vSLAM, referring to aconfiguration wherein the input is images/visual only) process. Thesystem can be configured to not only find out where in the world thevarious components are, but what the world is made of. Pose may be abuilding block that achieves many goals, including populating the mapand using the data from the map.

In one embodiment, a sparse point position may not be completelyadequate on its own, and further information may be needed to produce amultifocal AR, VR, or MR experience. Dense representations, generallyreferring to depth map information, may be utilized to fill this gap atleast in part. Such information may be computed from a process referredto as Stereo 940, wherein depth information is determined using atechnique such as triangulation or time-of-flight sensing. Imageinformation and active patterns (such as infrared patterns created usingactive projectors), images acquired from image cameras, or handgestures/totem 950 may serve as input to the Stereo process 940. Asignificant amount of depth map information may be fused together, andsome of this may be summarized with a surface representation. Forexample, mathematically definable surfaces may be efficient (e.g.,relative to a large point cloud) and digestible inputs to otherprocessing devices like game engines. Thus, the output of the stereoprocess (e.g., a depth map) 940 may be combined in the fusion process930. Pose 910 may be an input to this fusion process 930 as well, andthe output of fusion 930 becomes an input to populating the map process920. Sub-surfaces may connect with each other, such as in topographicalmapping, to form larger surfaces, and the map becomes a large hybrid ofpoints and surfaces.

To resolve various aspects in a mixed reality process 960, variousinputs may be utilized. For example, in the embodiment depicted in FIG.9 , Game parameters may be inputs to determine that the user of thesystem is playing a monster battling game with one or more monsters atvarious locations, monsters dying or running away under variousconditions (such as if the user shoots the monster), walls or otherobjects at various locations, and the like. The world map may includeinformation regarding the location of the objects or semanticinformation of the objects and the world map can be another valuableinput to mixed reality. Pose relative to the world becomes an input aswell and plays a key role to almost any interactive system.

Controls or inputs from the user are another input to the wearablesystem 900. As described herein, user inputs can include visual input,gestures, totems, audio input, sensory input, etc. In order to movearound or play a game, for example, the user may need to instruct thewearable system 900 regarding what he or she wants to do. Beyond justmoving oneself in space, there are various forms of user controls thatmay be utilized. In one embodiment, a totem (e.g. a user input device),or an object such as a toy gun may be held by the user and tracked bythe system. The system preferably will be configured to know that theuser is holding the item and understand what kind of interaction theuser is having with the item (e.g., if the totem or object is a gun, thesystem may be configured to understand location and orientation, as wellas whether the user is clicking a trigger or other sensed button orelement which may be equipped with a sensor, such as an IMU, which mayassist in determining what is going on, even when such activity is notwithin the field of view of any of the cameras.)

Hand gesture tracking or recognition may also provide input information.The wearable system 900 may be configured to track and interpret handgestures for button presses, for gesturing left or right, stop, grab,hold, etc. For example, in one configuration, the user may want to flipthrough emails or a calendar in a non-gaming environment, or do a “fistbump” with another person or player. The wearable system 900 may beconfigured to leverage a minimum amount of hand gesture, which may ormay not be dynamic. For example, the gestures may be simple staticgestures like open hand for stop, thumbs up for ok, thumbs down for notok; or a hand flip right, or left, or up/down for directional commands.

Eye tracking is another input (e.g., tracking where the user is lookingto control the display technology to render at a specific depth orrange). In one embodiment, vergence of the eyes may be determined usingtriangulation, and then using a vergence/accommodation model developedfor that particular person, accommodation may be determined. Eyetracking can be performed by the eye camera(s) to determine eye gaze(e.g., direction or orientation of one or both eyes). Other techniquescan be used for eye tracking such as, e.g., measurement of electricalpotentials by electrodes placed near the eye(s) (e.g.,electrooculography).

Speech tracking can be another input can be used alone or in combinationwith other inputs (e.g., totem tracking, eye tracking, gesture tracking,etc.). Speech tracking may include speech recognition, voicerecognition, alone or in combination. The system 900 can include anaudio sensor (e.g., a microphone) that receives an audio stream from theenvironment. The system 900 can incorporate voice recognition technologyto determine who is speaking (e.g., whether the speech is from thewearer of the wearable device or another person or voice (e.g., arecorded voice transmitted by a loudspeaker in the environment)) as wellas speech recognition technology to determine what is being said. Thelocal data & processing module 260 or the remote processing module 270can process the audio data from the microphone (or audio data in anotherstream such as, e.g., a video stream being watched by the user) toidentify content of the speech by applying various speech recognitionalgorithms, such as, e.g., hidden Markov models, dynamic time warping(DTW)-based speech recognitions, neural networks, deep learningalgorithms such as deep feedforward and recurrent neural networks,end-to-end automatic speech recognitions, machine learning algorithms(described with reference to FIG. 7 ), or other algorithms that usesacoustic modeling or language modeling, etc.

Another input to the mixed reality process 960 can include eventtracking. Data acquired from the outward facing imaging system 464 canbe used event tracking, and the wearable system can analyze such imaginginformation (using computer vision techniques) to determine if atriggering event is occurring that may beneficially cause the system toautomatically mute the visual or audible content being presented to theuser.

The local data & processing module 260 or the remote processing module270 can also apply voice recognition algorithms which can identify theidentity of the speaker, such as whether the speaker is the user 210 ofthe wearable system 900 or another person with whom the user isconversing. Some example voice recognition algorithms can includefrequency estimation, hidden Markov models, Gaussian mixture models,pattern matching algorithms, neural networks, matrix representation,Vector Quantization, speaker diarisation, decision trees, and dynamictime warping (DTW) technique. Voice recognition techniques can alsoinclude anti-speaker techniques, such as cohort models, and worldmodels. Spectral features may be used in representing speakercharacteristics. The local data & processing module or the remote dataprocessing module 270 can use various machine learning algorithmsdescribed with reference to FIG. 7 to perform the voice recognition.

With regard to the camera systems, the example wearable system 900 shownin FIG. 9 can include three pairs of cameras: a relative wide FOV orpassive SLAM pair of cameras arranged to the sides of the user's face, adifferent pair of cameras oriented in front of the user to handle thestereo imaging process 940 and also to capture hand gestures andtotem/object tracking in front of the user's face. The FOV cameras orthe pair of cameras for stereo process 940 may also be referred to ascameras 16. The FOV cameras and the pair of cameras for the stereoprocess 940 may be a part of the outward-facing imaging system 464(shown in FIG. 4 ). The wearable system 900 can include eye trackingcameras (which also were shown as eye cameras 24 and which may be a partof an inward-facing imaging system 462 shown in FIG. 4 ) oriented towardthe eyes of the user in order to triangulate eye vectors and otherinformation. The wearable system 900 may also comprise one or moretextured light projectors (such as infrared (IR) projectors) to injecttexture into a scene.

Examples of a Wearable System Including Environmental Sensors

FIG. 10 shows a schematic view of an example of various components of anwearable system comprising environmental sensors. In some embodiments,the augmented reality display system 1010 may be an embodiment of thedisplay system 100 illustrated in FIG. 2 . The AR display system 1010may be a mixed reality display system in some implementations. Theenvironmental sensors may include sensors 24, 28, 30, 32, and 34. Anenvironmental sensor may be configured to detect data regarding the userof the AR system (also referred to as a user sensor) or be configured tocollect data regarding the user's environment (also referred to as anexternal sensor). For example, a physiological sensor may be anembodiment of a user sensor while a barometer may be an external sensor.In some situations, a sensor may be both a user sensor and an externalsensor. For example, an outward-facing imaging system may acquire animage of the user's environment as well as an image of the user when theuser is in front of a reflective surface (such as, e.g., a mirror). Asanother example, a microphone may serve as both the user sensor and theexternal sensor because the microphone can acquire sound from the userand from the environment. In the example illustrated in FIG. 10 , thesensors 24, 28, 30, and 32 may be user sensors while the sensor 34 maybe an external sensor.

As illustrated, an augmented reality display system 1010 may includevarious user sensors. The augmented reality display system 1010 mayinclude a viewer imaging system 22. The viewer imaging system 22 may bean embodiment of the inward-facing imaging system 466 described in FIG.4 . The viewer imaging system 22 may include cameras 24 (e.g., infrared,UV, and/or visible light cameras) paired with light sources 26 (e.g.,infrared light sources) directed at and configured to monitor the user(e.g., the eyes 1001, 1002 and/or surrounding tissues of the user). Thecameras 24 and light sources 26 may be operatively coupled to the localprocessing module 270. Such cameras 24 may be configured to monitor oneor more of the orientation, shape, and symmetry of pupils (includingpupil sizes) or irises of the respective eyes, and/or tissuessurrounding the eye, such as eyelids or eyebrows to conduct the variousanalyses disclosed herein. In some embodiments, imaging of the irisand/or retina of an eye may be used for secure identification of a user.With continued reference to FIG. 10 , cameras 24 may further beconfigured to image the retinas of the respective eyes, such as fordiagnostic purposes and/or for orientation tracking based on thelocation of retinal features, such as the fovea or features of thefundus. Iris and retina imaging or scanning may be performed for secureidentification of users for, e.g., correctly associating user data witha particular user and/or to present private information to theappropriate user. In some embodiments, in addition to or as analternative to the cameras 24, one or more cameras 28 may be configuredto detect and/or monitor various other aspects of the status of a user.For example, one or more cameras 28 may be inward-facing and configuredto monitor the shape, position, movement, color, and/or other propertiesof features other than the eyes of the user, e.g., one or more facialfeatures (e.g., facial expression, voluntary movement, involuntarytics). In another example, one or more cameras 28 may be downward-facingor outward-facing and configured to monitor the position, movement,and/or other features or properties of the arms, hands, legs, feet,and/or torso of a user, of another person in the user's FOV, objects inthe FOV, etc. The cameras 28 may be used to image the environment, andsuch images can be analyzed by the wearable device to determine whethera triggering event is occurring such that the visual or audible contentbeing presented to the user by the wearable device should be muted.

In some embodiments, as disclosed herein, the display system 1010 mayinclude a spatial light modulator that variably projects, through afiber scanner (e.g., the image injection devices in FIGS. 4 —420, 422,424, 426, 428), light beams across the retina of the user to form animage. In some embodiments, the fiber scanner may be used in conjunctionwith, or in place of, the cameras 24 or 28 to, e.g., track or image theuser's eyes. For example, as an alternative to or in addition to thescanning fiber being configured to output light, the health system mayhave a separate light-receiving device to receive light reflected fromthe user's eyes, and to collect data associated with that reflectedlight.

With continued reference to FIG. 10 , the cameras 24, 28 and lightsources 26 may be mounted on the frame 230, which may also hold thewaveguide stacks 1005, 1006. In some embodiments, sensors and/or otherelectronic devices (e.g., the cameras 24, 28 and light sources 26) ofthe display system 1010 may be configured to communicate with the localprocessing and data module 270 through communication links 262, 264.

In some embodiments, in addition to providing data regarding the user,one or both of the cameras 24 and 28 may be utilized to track the eyesto provide user input. For example, the viewer imaging system 22 may beutilized to select items on virtual menus, and/or provide other input tothe display system 2010, such as for providing user responses in thevarious tests and analyses disclosed herein.

In some embodiments, the display system 1010 may include motion sensors32, such as one or more accelerometers, gyros, gesture sensors, gaitsensors, balance sensors, and/or IMU sensors. The sensors 30 may includeone or more inwardly directed (user directed) microphones configured todetect sounds, and various properties of those sound, including theintensity and type of sounds detected, the presence of multiple signals,and/or signal location.

The sensors 30 are schematically illustrated as being connected to theframe 230. It will be appreciated that this connection may take the formof a physical attachment to the frame 230 and may be anywhere on theframe 230, including the ends of the temples of the frame 230 whichextend over the user's ears. For example, the sensors 30 may be mountedat the ends of the temples of the frame 230, at a point of contactbetween the frame 230 and the user. In some other embodiments, thesensors 30 may extend away from the frame 230 to contact the user 210.In yet other embodiments, the sensors 30 may not be physically attachedto the frame 230; rather, the sensors 30 may be spaced apart from theframe 230.

In some embodiments, the display system 1010 may further include one ormore environmental sensors 34 configured to detect objects, stimuli,people, animals, locations, or other aspects of the world around theuser. For example, environmental sensors 34 may include one or morecameras, altimeters, barometers, chemical sensors, humidity sensors,temperature sensors, external microphones, light sensors (e.g., lightmeters), timing devices (e.g., clocks or calendars), or any combinationor subcombination thereof. In some embodiments, multiple (e.g., two)microphones may be spaced-apart, to facilitate sound source locationdeterminations. In various embodiments including environment sensingcameras, cameras may be located, for example, facing outward so as tocapture images similar to at least a portion of an ordinary field ofview of a user. Environmental sensors may further include emissionsdevices configured to receive signals such as laser, visible light,invisible wavelengths of light, sound (e.g., audible sound, ultrasound,or other frequencies). In some embodiments, one or more environmentalsensors (e.g., cameras or light sensors) may be configured to measurethe ambient light (e.g., luminance) of the environment (e.g., to capturethe lighting conditions of the environment). Physical contact sensors,such as strain gauges, curb feelers, or the like, may also be includedas environmental sensors.

In some embodiments, the display system 1010 may further be configuredto receive other environmental inputs, such as GPS location data,weather data, date and time, or other available environmental data whichmay be received from the internet, satellite communication, or othersuitable wired or wireless data communication method. The processingmodule 260 may be configured to access further informationcharacterizing a location of the user, such as pollen count,demographics, air pollution, environmental toxins, information fromsmart thermostats, lifestyle statistics, or proximity to other users,buildings, or a healthcare provider. In some embodiments, informationcharacterizing the location may be accessed using cloud-based or otherremote databases. The processing module 260 may be configured to obtainsuch data and/or to further analyze data from any one or combinations ofthe environmental sensors.

The display system 1010 may be configured to collect and store dataobtained through any of the sensors and/or inputs described above forextended periods of time. Data received at the device may be processedand/or stored at the local processing module 260 and/or remotely (e.g.,as shown in FIG. 2 , at the remote processing module 270 or remote datarepository 280). In some embodiments, additional data, such as date andtime, GPS location, or other global data may be received directly at thelocal processing module 260. Data regarding content being delivered tothe user by the system, such as images, other visual content, orauditory content, may be received at the local processing module 260 aswell.

Automatic Control of a Wearable Display System

As described above, situations may occur where it is desirable or evennecessary to deemphasize or block virtual content, or even turn off thedisplay of virtual content by the wearable device. Such situations canoccur in response to triggering events, such as, e.g., emergencysituations, unsafe situations, or situations where it may be desirablefor the user of the wearable device to be presented less virtual contentso that the user can focus more attention on the physical world outsidethe user. The triggering events can also be based on the environment inwhich the user is using the system. A wearable system can block virtualcontent or present tailored virtual content based on the user'senvironment. For example, the wearable system can block video games ifthe wearable system detects that the user is at work.

Embodiments of the wearable device disclosed herein may includecomponents and functionality that can determine if such a situation isoccurring and take an appropriate action to mute the wearable system,such as, e.g., by muting the virtual content (e.g., deemphasize, block,or turn off the display of virtual content), or by muting one or morecomponents of the wearable system (such as, e.g., turn off, attenuate,put into sleep mode of the one or more components). As used herein,muting virtual content can generally include deemphasizing, attenuating,or reducing the quantity or impact of the visual or audible contentpresented to the user by the wearable device, up to and includingturning the content off. Muting can include a visible mute (e.g.,turning off or dimming the display 220) or an audible mute (e.g.,reducing the sound emitted by the speaker 240 or turning the speakerscompletely off). Muting can include increasing the transparency ofvisible virtual content, which makes it easier for the user to seethrough such virtual content to perceive the outside physical world.Muting can also include decreasing the size of the virtual content oraltering its placement so that it is less prominent in the field of viewof the user. Muting can further include blocking content from thedisplay by the wearable device or selectively allowing some content butnot allowing other content. Accordingly, muting can be implemented via ablacklist (which identifies the content to be blocked) or via awhitelist (which identifies the content to be allowed). In someimplementations, a combination of blacklisting and whitelisting can beused to effectively mute content. Additionally or alternatively, agreylist can be used to indicate content that should temporarily beblocked (or allowed) until another condition or event occurs. Forexample, in an office environment, certain virtual content could begreylisted and temporarily blocked for display to a user, until theuser's supervisor overrides the block and moves the content to awhitelist or permanently blocks the content by moving the content to ablacklist. Various embodiments of the wearable device described hereincan use some or all of the foregoing techniques to mute the virtualcontent presented to the user.

In the following, various non-limiting, illustrative examples of userexperiences will be described in which it may be desirable to mute thevirtual content. Following these examples, techniques and apparatus fordetermining that an event is occurring that triggers the wearable deviceto mute the virtual content will be described.

Examples of Muting a Wearable Device in a Surgical Context

FIGS. 11A and 11B illustrate an example of muting an HMD in a surgicalcontext. In FIG. 11A, a surgeon is performing a surgery on a heart 1147.The surgeon may wear the HMD described herein. The surgeon can perceivethe heart 1147 in his FOV. The surgeon can also perceive virtual objects1141, 1142, and 1145 in his FOV. The virtual objects 1141, 1142, and1145 may be related to various metrics (such as e.g., heart rate, ECG,etc.) associated with the heart as well as diagnosis, such as, e.g.,arrhythmia, cardiac arrest, etc.). The HMD can present the virtualobjects 1141, 1142, and 1145 based on information acquired by thewearable system's environmental sensors or by communicating with anotherdevice or the remote processing module of the wearable system.

However, during the surgery, an unanticipated or emergency situation mayoccur. For example, there may be a sudden, unwanted flow of blood at thesurgical site (as shown by the spray 1149 of blood from the heart 1147in FIG. 11B). The wearable system may detect this situation usingcomputer vision techniques, for example, by detecting (in imagesacquired by an outward-facing camera) rapidly occurring changes inkeypoints or features in or near the surgical site. The wearable systemmay also make the detection based on the data received from the otherdevice or the remote processing module.

The wearable system may determine that this situation meets the criteriafor a triggering event in which the display of visual or audible virtualcontent should be muted so that the surgeon can focus attention on theunexpected or emergency situation. Accordingly, the wearable system mayautomatically mute the virtual content in response to automaticdetection of the triggering event (in this example, the spray 1149 ofblood). As a result, in FIG. 11B, the surgeon is not presented with thevirtual objects 1141, 1142, and 1145 by the HMD, and the surgeon canfocus all his attention on stopping the eruption of blood.

The HMD may resume normal operations and restore presentation of virtualcontent to the surgeon in response to a termination event. Thetermination event may be detected when the triggering event is over(e.g., the blood stops spraying) or when user enters another environmentin which the triggering event is not present (e.g., when the user walksout of the emergency room). The termination event can also be based on athreshold period of time. For example, the HMD may resume normaloperations after a period of time has elapsed (e.g., 5 minutes, 15minutes, 1 hour, etc.) upon the detection of the triggering event orupon the detection that the triggering event is over for the period oftime. In this example, the wearable system can resume the display (orother components of the wearable system) before the triggering event isover.

Examples of Muting the Wearable Device in an Industrial Context

Similar techniques for muting the HMD can also be applied in othercontexts. For example, the techniques may be used in an industrialcontext. As an example, a worker may be welding a metal workpiece in afactory while wearing the HMD. The worker can perceive, through the HMD,the metal which he is working on as well as the virtual contentassociated with the welding process. For example, the HMD can displayvirtual content including instructions for how to weld a component.

However, an unanticipated or emergency situation may happen while theworker is using the HMD. For example, the worker's clothes mayaccidentally catch fire or the welding torch may overheat or set fire tothe workpiece or nearby materials. Other emergency situations may occursuch as a spill of industrial chemicals in the worker's environment. Thewearable system can detect these situations as events triggering the HMDto mute the virtual content. As further described with reference toFIGS. 12A-12C, the wearable system can detect the triggering eventsusing a computer vision algorithm (or a machine learning algorithm) byanalyzing images of the worker's environment. For example, to detect afire or overheating, the wearable system may analyze infrared (IR)images taken by the outward facing camera, since the heat from fires oroverheating will be particularly apparent in IR images. The wearablesystem can automatically mute the display of virtual content in responseto the detection of the triggering event. In some situations, thewearable system may provide an alert indicating that the HMD will beautomatically turned off unless the user indicates otherwise.

In certain embodiments, the worker can manually actuate a reality button263, which may cause the HMD to mute the virtual content. For example,the worker may sense the emergency or unsafe condition (e.g., bysmelling the overheated materials) and actuate the reality button sothat the worker can more readily focus on the actual reality. To avoidaccidentally muting the virtual content when the worker is stillinterested in the virtual content, the HMD may provide an alert to theworker prior to performing the mute operation. For example, upondetecting the actuation of the reality button, the HMD may provide amessage to the worker indicating that the virtual content will be mutedshortly (e.g. in a few seconds) unless the worker indicates otherwise(such as by actuating the reality button again or by a change in hispose). Further details regarding such an alert are described below withreference to FIGS. 14A and 14B.

FIG. 11C shows a landscaping worker operating machinery (e.g., a lawnmower). Like many repetitive jobs, cutting grass can be tedious. Workersmay lose interest after some period of time, increasing the probabilityof an accident. Further, it may be difficult to attract qualifiedworkers, or to ensure that workers are performing adequately.

The worker shown in FIG. 11C wears an HMD, which renders virtual content1130 in the user's field of view to enhance job performance. Forexample, as illustrated in the scene 1100 c, the HMD may render avirtual game, where the goal is to follow a virtually mapped pattern.Points are received for accurately following the pattern and hittingcertain score multipliers before they disappear. Points may be deductedfor straying from the pattern or straying too close to certain physicalobjects (e.g., trees, sprinkler heads, roadway).

However, the worker may encounter an incoming vehicle which may drive ata very fast speed or a pedestrian may walk in front of the machinery.The worker may need to react to this incoming vehicle or the pedestrian(such as by slowing down or changing directions). The wearable systemcan use its outward-facing imaging system to acquire images of theworker's surroundings and use computer vision algorithms to detect theincoming vehicle or the pedestrian.

The wearable system can calculate the speed or distance from the workerbased on the acquired images (or location based data acquired from otherenvironmental sensors, such as a GPS). If the wearable system determinesthat the speed or the distance passes a threshold condition (e.g., thevehicle is approaching very fast or the vehicle or pedestrian is veryclose to the worker), the HMD may automatically mute the virtual content(e.g., by pausing the game, moving the virtual game to be outside of theFOV) to reduce distractions and to allow the worker to concentrate onmaneuvering the lawn mower to avoid the incoming vehicle or pedestrian.For example, as shown in the scene 1132 c, when the HMD mutes thevirtual content, the user does not perceive the virtual game component1130.

When the wearable system detects a termination condition, such as e.g.,when the triggering event is over, the HMD may resume normal operationsand restore presentation of virtual content to the worker. In someimplementations, the HMD may mute the virtual content while the rest ofthe HMD may continue to operate. For example, the wearable system maycontinuously image the user's position using one or more environmentalsensors (such as the GPS or the outward-facing camera). When wearablesystem determines that incoming vehicle or the pedestrian has passed theworker, the wearable system may turn the virtual content back on.

In some implementations, the wearable system can present an alert beforeresuming normal operations or restoring presentation of the virtualcontent. This can prevent the virtual content to be turned on when thetriggering event is still ongoing (e.g., when a user is still in anemergency), if the user needs time to recover after the emergency, orfor any other reason. In response to the alert, the user can actuate thereality button 263 if the user would like to virtual content to remainmuted. In some implementations, the user can resume virtual contentduring the triggering event, through a manual user input orautomatically. This allows for situations where the virtual contentcould help the user during the triggering event. For example, the systemmay automatically detect a child is choking, and thus mute the parent'svirtual content. If the system has an emergency response applicationinstalled, the system may automatically selectively turn on only thevirtual content related to the emergency response application if theparent does not respond within a threshold period of time, or if theparent does not take the correct action.

Examples of Muting the Wearable Device in an Educational Context

FIG. 11D illustrates an example of muting the HMD in an educationalcontext. FIG. 11D shows a classroom 1100 d with two students 1122 and1124 physically sitting in the classroom (in this example, the class isa yoga class). While the students 1122 and 1124 are wearing the HMD,they can perceive a virtual avatar for a student 1126 and a virtualavatar for a teacher 1110, neither of whom are physically present in theroom. The student 1126 may participate in a class in his house (ratherthan in the classroom 1100 d).

In one situation, the student 1122 may want to discuss with the otherstudent 1124 a class-related problem during the class (e.g., how toperform a particular yoga pose). The student 1122 may walk to thestudent 1124. The wearable system of the student 1124 may detect thatthe other student 1122 is in front of her and automatically mute theaudio and virtual content presented by the HMD to allow the students1124 and 1122 to interact in person, with less (or no) virtual contentbeing presented. For example, the wearable system may use a facialrecognition algorithm to detect the presence of a physical person infront of the HMD (which may be an example of a triggering event thatcauses the HMD to automatically mute the virtual content). In responseto this detection, the HMD can turn off (or attenuate) the audio andvirtual content from the HMD. In the example shown in FIG. 11D, once theHMD of the student 1124 is muted, the student 1124 will not be able toperceive the virtual avatars 1126 and 1110. However, the student 1124can still see and interact with the student 1122 who is also in thephysical classroom.

As another example, the teacher 1110 may tell the students to engage ingroup discussions and the students 1122 and 1124 may be classified intothe same group. In this example, the HMD may mute the virtual contentand to allow the students 1112 and 1124 to engage in a face-to-facediscussion. The HMD can also reduce the size of the virtual avatars 1110and 1126 to reduce perceptual confusion during the group discussion.

Examples of Muting the Wearable Device in an Entertainment Context

The wearable system can also detect a triggering event and mute theaudio/visual content in an entertainment context. For example, thewearable system can monitor the user's physiological data while a useris playing a game. If the physiological data indicates that the user isexperiencing an agitated emotional state (such as being extremely angrydue to a loss in a game or extremely scared during a game), the wearablesystem may detect the presence of a triggering event and thus can causethe HMD to automatically mute the virtual content. The wearable systemcan compare the physiological data with one or more thresholds for thedetection of the triggering event. As an example, the wearable systemcan monitor the user's heart rate, respiratory rate, pupil dilation,etc. The threshold conditions may depend on the type of game the user isplaying. For example, if the user is playing a relatively relaxing game(such as a life simulation game), the threshold condition (e.g., thethreshold hear rate, respiratory rate, etc.) may be lower than if theuser is playing a racing game (which may require intense concentrationand can cause the user's heart rate to go up). If the user'sphysiological state passes the threshold, then the wearable system istriggered to mute the virtual content provided by the HMD.

As another example, virtual content may be associated with unpleasantmusic. The unpleasant music may be a triggering event for muting theaudio/visual content of the HMD. The wearable system can detect theuser's reaction using the inward-facing imaging system (e.g., todetermine the user's facial expression or pupil dilation) or otherenvironmental sensors (e.g., to detect the user's respiratory rate orheart rate). For example, the wearable system may detect that the userfrowns when the user hears certain music.

The wearable system can generate an alert message indicating that theuser is experiencing an agitated emotional state. The HMD may display avirtual graphic that suggests the user manually actuate the realitybutton 263 to mute display of the virtual content. In some embodiments,the HMD may automatically turn off the virtual content if the HMD doesnot receive the user confirmation within a certain period of time. TheHMD may also automatically turn off the virtual content in response tothe detection of the triggering event. For example, when an unpleasantmusic is played, the HMD may automatically mute the sound or lower thevolume of the sound. In the meantime, the HMD may still play the virtualimages associated with the sound.

Examples of Muting the Wearable Device in a Shopping Context

FIG. 11E illustrates an example of muting an HMD in a shopping context.

In this example, the user 210 may wear an HMD in a shopping mall 1100 e.The user 210 can perceive virtual content such as her shopping list,price tags, recommended items (and their locations in the store), etc.,using the HMD. The user can also perceive a physical booth 1150 with achef 1152 selling various spices and cooking utensils.

The wearable system can detect the user's 210 position usingenvironmental sensors (such as GPS or outward-facing imaging system). Ifthe wearable system determines that the user 210 is within a thresholddistance of the booth 1150, the HMD may automatically mute the displayof virtual content so that the user can interact with the chef 1152 inperson. This may advantageously reduce perceptual confusion when theuser 210 engages in a conversion with the chef 1152. Further, forexample, the user may be able to tell which items in the booth arephysical items (rather than virtual items). The wearable system candetect a termination condition, such as, e.g., when the user 210 walksaway from the booth 1150, the HMD may unmute the display of virtualcontent in response to the detection of the termination condition.

Examples of Muting Virtual Content Based on Environment

In addition to or in alternative to muting virtual content based onevents in the environments (e.g., emergency situations) or objects inthe environment (e.g., the presence of another user's face), thewearable system can also mute virtual content based on thecharacteristics of the user's environment. For example, the wearablesystem can identify such characteristics of the user's environment basedon the objects observed by the outward-facing imaging system 464. Basedon the type of the user's environment (e.g., home, office, break orgaming area, outdoors, retail store, mall, theater or concert venue,restaurant, museum, transportation (e.g., automobile, plane, bus,train), etc.), the wearable system can tailor virtual content or mutecertain virtual content.

Additionally or alternatively to using the wearable system'soutward-facing imaging system 464, as will be further described herein,the wearable system may use a location sensor (e.g., a GPS sensor) todetermine the user's location and thereby infer the nature of the user'senvironment. For example, the wearable system may store locations ofinterest to the user (e.g., a home location, an office location, etc.).The location sensor can determine location, compare to a known locationof interest, and the wearable system can infer the user's environment(e.g., if the GPS coordinates of the system are sufficiently close tothe user's home location, the wearable system can determine that theuser is in a home environment and apply appropriate content blocking (orallowing) based on the home environment).

As one example, the wearable system can include a variety of virtualcontent such as, e.g., virtual content related to social media, gameinvitations, audiovisual content, office content, and navigationapplications. The outward-facing imaging system 464 can detect that auser is in an office (e.g., by recognizing the presence of a computermonitor, business telephone, work files on an office desk using objectrecognizers). The wearable system can accordingly allow officeapplications and block the social media feeds and gaming invitations sothat the user can focus on work. The wearable system, however, may beconfigured not to mute the navigation applications because they may behelpful to direct the user to a client destination. However, when thewearable system detects that the user is sitting in a chair in theoffice that is away from the user's desk (e.g., with analysis of imagesacquired by the outward-facing imaging system), the wearable system maybe configured to allow social media feeds, alone or in combination withthe office (or navigation) applications, as the user might be taking ashort break. Additionally or alternatively, the wearable system canlabel environment and specify what content is to be blocked or allowedbased on user input. For example, the wearable system can receive anindication from a user that a scene is the user's bedroom, and the usercan select the option of allowing entertainment content or blocking workcontent at the scene. Thus, when the user re-enters the bedroom, thesystem can determine that the user is in the bedroom, and automaticallyblock or allow content based on the user input.

In some situations, the wearable system can mute or present virtualcontent based on a combination of environment and user's role withrespect to the environment. For example, the wearable system can presenta set of office tools for an employee and block access to the Internet(or other applications) when the wearable system detects that the useris in the office (e.g., by identifying office furniture using objectrecognizers 708). However, if a supervisor enters into the same officeenvironment, the wearable system may allow the supervisor to access toInternet because the supervisor may have more access to virtual content.

As another example, the wearable system can recognize that a user is ina house, such as, e.g., by recognizing the presence of home furniture(e.g., sofa, television, dining tables, etc.) in an environment or bymanual labeling, by the user, for example. The wearable system canaccordingly allow certain virtual content, such as, e.g., social mediafeeds, video games, or telepresence invitations from/to friends. Incertain implementations, even though two users are in the sameenvironment, the virtual content perceivable by the user may bedifferent. For example, a child and a parent can both be in a livingenvironment, but the wearable system can block the virtual content notappropriate to the child's age while allowing the parent to view suchvirtual content. Additional examples of muting virtual content based onlocations are further described below with reference to FIGS. 11F and11G.

Although the examples are described with reference to blocking thevirtual content, the wearable system can also mute the virtual contentbased on location by, e.g., deemphasizing some or all of the virtualcontent or turning off the display based on the location.

Examples of Selective Content Muting in a Work Environment

FIG. 11F illustrates an example of selectively blocking content in awork environment. FIG. 11F shows two scenes 1160 a and 1160 b, wheresome virtual content is blocked in the scene 1160 b. Scenes 1160 a and1160 b show an office 1100 f with a user 210 physically standing in theoffice. The user 210 can wear an HMD 1166 (which may be an embodiment ofthe HMD described with reference to FIG. 2 ). The user can perceive, viathe HMD, physical objects in the office, such as, e.g., a table 1164 a,a chair 1164 b, and a mirror 1164 c. The HMD can also be configured topresent virtual objects such as, e.g., a virtual menu 1168 and a virtualavatar 1164 for a game.

In some situations, the wearable system can be configured to selectivelymute virtual content in the user's environment such that not all virtualcontent is presented to the user by the HMD 1166. As one example, thewearable system can receive data about the environment acquired from oneor more environmental sensors of the wearable system. The environmentaldata may include images of the office alone or in combination of GPSdata. The environmental data can be used to recognize objects in theuser's environment or to determine the user's location based on therecognized objects. With reference to FIG. 11F, the wearable system cananalyze the environmental data to detect the physical presence of a workdesk 1164 a, a chair 1164 b, and a mirror 1164 c. Based at least in parton the received data detecting the work desk 1514, the chair 1512, andthe mirror 1164 c, the wearable system 200 may recognize the environmentto be an office environment. For example, the wearable system can makethis determination based on contextual information associated with theobjects, such as, e.g., characteristics of the objects as well as layoutof objects. The collection of the objects in the user's environment canalso be used to determine a probability that a user is at a certainlocation. As one example, the wearable system can determine that thepresence of an L-shaped desk and a rolling chair indicates a highlikelihood that the environment is an office. The wearable system cantrain and apply a machine learning model (e.g., a neural network) todetermine the environment. Various machine learning algorithms (such asa neural network or supervised learning) may be trained and used forrecognizing the environment. In various embodiments, one or more objectrecognizers 708 can be used for such recognition. Alternatively, theuser may have previously labeled this location as “work” through a userinput.

Based on the environment, the wearable system can automaticallyblock/unblock (or allow/disallow) certain virtual content. The wearablesystem can access one or more settings associated with the environmentfor blocking the virtual content. With reference to FIG. 11F, a settingassociated with the office environment may include muting the videogames. Thus, as shown in the scene 1160 b, the wearable system mayautomatically block the virtual avatar 1524 from being rendered by theHMD 1166 to allow the user 210 to focus on his work. As another example,the wearable system can be configured to render an image of the virtualavatar 1164, but nevertheless block one or more user interfaceoperations associated with the virtual avatar 1164. In this example, theuser 210 will still be able to see the virtual avatar 1164, but the user210 cannot interact with virtual avatar 1164 while the wearable systemenables the setting associated with the work environment.

In certain implementations, the setting for muting virtual content at alocation can be user configurable. For example, a user can select whichvirtual content to block for an environment and what label to apply tothat location and/or virtual content selection. With reference to FIG.11F, the user 210 can select to block virtual avatar 1164 from appearingin the HMD while the user 210 is in the office 1100 f. The wearablesystem can then store the setting associated with office 1100 f andapply the setting to selectively block the virtual avatar 1164. Thus, asshown in the scene 1160 b, the virtual avatar 1164 is blocked from theuser's view.

The examples are described with reference to determining an environment(e.g., an office) and mute virtual content based on the environment, thewearable system can also mute the virtual content (or a component of thewearable system) based on the environmental factors or the similarity ofthe content to other blocked content, so that the wearable system doesnot have to determine the specific location of the user. This may beadvantageous if the wearable system does not include a location sensor,the location sensor is blocked (e.g., path to GPS satellites isblocked), or the location accuracy is insufficient to determine theenvironmental characteristics. The wearable system can recognize theobjects in an environment and determine characteristics of theenvironment (e.g., a leisure environment, a public environment, or awork environment) in general and mute virtual content based on thecharacteristics of the environment. For example, the wearable system canidentify that the user's environment includes a sofa and a television.The wearable system can thus determine that a user is in a leisureenvironment, without knowing whether the leisure environment is actuallythe user's home or a break room at the user's work. In someimplementations, the system will determine the type of environment andprovide a notification to the user to either accept or deny theenvironment label.

Examples of Selective Content Blocking in a Break Room Environment

FIG. 11G illustrates examples of selectively blocking content in a breakroom environment. FIG. 11G shows two scenes 1170 a and 1170 b. The breakroom 1100 g shown in FIG. 11G shows a user 210 wearing an HMD 1166 andphysically standing in the break room 1100 g. The break room 1100 gincludes physical objects such as a table 1172 c, a sofa 1172 b, and atelevision 1172 a. The HMD 1166 can also be configured to presentvirtual content, such as, e.g., a virtual avatar 1176 for a game and avirtual menu 1174, neither of which are physically present in the room.In this example, virtual menu 1174 presents options 1178 a, 1178 b, 1178c to the user 210 to play a crossword, start a conference call, oraccess work email respectively.

The wearable system can be configured to mute some virtual content basedon the user's environment. For example, the outward-facing imagingsystem 464 can acquire images of the user's environment. The wearablesystem can analyze the images and detect the physical presence of acoffee table 1172 c, a sofa 1172 b, and a television 1172 a. Based atleast in part on the presence of the coffee table 1172 c, the sofa 1172b, and the television 1172 a, the wearable system 200 may then recognizethat the user 210 is in a break room environment.

The wearable system can render or mute virtual content based on one ormore settings associated with the user's environment. The setting caninclude muting some virtual content in the environment or muting aportion of the virtual content. As an example of muting some virtualcontent, the wearable system can block the virtual avatar 1176 fromdisplaying while keeping the virtual menu 1174. As an example ofblocking a portion of the virtual content, the scene 1170 b illustratesan example of blocking work related content when a user is in a breakroom. As shown in the scene 1170 b, rather than blocking the wholevirtual menu 1174, the wearable system can selectively block theconference option 1178 b and work email option 1178 c but keep crosswordoption 1178 a available for interaction because the crossword option1178 a is entertainment related while the options 1178 b and 1178 c arework related and the setting associated with the breakroom environmentenables blocking of the work related content. In certainimplementations, the conference option 1178 b and 1178 c may still bevisible to a user but the wearable system may prevent user interactionswith the options 1178 b and 1178 c while the user 210 is in the breakroom 1100 g.

In some implementations, the user can configure a mute settingassociated with an environment and the wearable system can automaticallyblock similar virtual content even though a particular piece of virtualcontent may not be part of the mute setting. For example, a user canconfigure a work setting for muting social networking applications. Thewearable system can automatically mute game invitations because the gameinvitations and the social networking applications are both consideredas entertainment activities. As another example, the wearable system maybe tailored to present work email and office tools in an officeenvironment. Based on this setting, the wearable system can also presentworked related contacts for telepresence tools to tailor the virtualcontent to the office environment. The wearable system can determinewhether virtual content is similar to those blocked (or tailored) usingone or more machine learning algorithms described with reference toobject recognizers 708 in FIG. 7 .

Although the examples in the scenes 1170 a and 1170 b are described withreference to blocking content based on the user's environment, in someimplementations, the settings associated with the environment may relateto allowing certain virtual content. For example, a setting associatedwith a break room environment can include enabling interactions withentertainment related virtual content.

Examples of a Triggering Event

FIGS. 12A, 12B, and 12C illustrate examples of muting virtual contentpresented by an HMD based at least partly on occurrence of a triggeringevent. In FIG. 12A, a user of an HMD can perceive physical objects inhis FOV 1200 a. The physical objects may include a television (TV) 1210,a remote control 1212, a TV stand 1214, and a window 1216. The HMD heremay be an embodiment of the display 220 described with reference toFIGS. 2 and 4 . The HMD can display the virtual objects onto thephysical environment of the user in an AR or MR experience. For example,in FIG. 12A, the user can perceive virtual objects such as a virtualbuilding 1222 and an avatar 1224 in the user's environment.

The user can interact with objects in the user's FOV. For example, theavatar 1224 may represent a virtual image of the user's friend. Whilethe user is conducting a telepresence session with his friend, theavatar 1224 may animate the user's friend's movements and emotions tocreate a tangible sense of the friend's presence in the user'senvironment. As another example, the user can interact with the TV 1210using the remote 1212 or using a virtual remote rendered by the HMD. Forexample, the user can change the channel, volume, sound settings, etc.using the remote 1212 or the virtual remote. As yet another example, theuser can interact with the virtual building 1222. For example, the usercan use poses (e.g., hand gestures or other body poses) or actuate auser input device (e.g., user input device 504 in FIG. 4 ) to select thevirtual building 1222. Upon selection of the virtual building, the HMDcan display a virtual environment inside of the virtual building 1222.For example, the virtual building 1222 may include virtual classroomsinside. The user can simulate walking into the virtual classrooms andengage in a class in an AR/MR/VR environment.

When the user is in an AR/MR/VR environment, the environmental sensors(including the user sensors and the external sensors) can acquire dataof the user and the user's environment. The wearable system can analyzethe data acquired by the environmental sensors to determine one or moretriggering events. Upon occurrence of a triggering event (which may havea magnitude or significance above a threshold), the wearable system canautomatically mute the virtual content, such as, e.g., by muting thedisplay of some or all of visible virtual content or muting audiblevirtual content.

A triggering event may be based on physical events occurring in theuser's environment. For example, a triggering event may include anemergency or unsafe situation such as a fire, an artery rupture (in asurgery), a police car approaching, spill of chemicals (in an experimentor industrial procedure), etc. The triggering event may also beassociated with a user's action, such as when a user walks on a crowdedstreet, sits in a car (which may be unsafe to drive if too much virtualcontent is presented to the user). The triggering event may also bebased on a user's location (e.g., at home or a park) or a scene (e.g., awork scene or a leisure scene) around the user. The triggering event canfurther be based on the objects (including other people) in the user'senvironment. For example, the triggering event may be based on thedensity of people within a certain distance of the user or computer facerecognition that a particular person (e.g., a teacher, police officer,supervisor, etc.) has approached the user.

Additionally or alternatively, the triggering event may be based onvirtual content. For example, the triggering event may include anunexpected loud noise in the AR/VR/MR environment. The triggering eventmay also include unpleasant or disturbing experiences in the AR/VR/MRenvironment. As yet another example, the wearable system may mute avirtual content similar to the virtual content that was previouslyblocked by the wearable system at a certain location.

The triggering event can also include a change in the user's location.FIG. 12D illustrates an example of muting virtual content upon detectinga change in a user's environment. In FIG. 12D, a user 210 is initiallyin a break room 1240 b. The user can perceive, via an HMD, virtualcontent tailored to the break room 1240 b, such as the example virtualcontents 1178 a and 1176 shown in the scene 1170 b in FIG. 11G. The user210 can walk out of the break room 1240 b and enter the office 1240 a.As the user 210 transitions from the break room 1240 b to the office1240 a, the wearable system 200 can acquire data from one or moreenvironmental sensors. The acquired data can include images acquired bythe outward-facing imaging system 464. The wearable system can analyzethe acquired images to detect the presence of a work desk 1242, a chair1244, and a computer monitor 1246. The wearable system 200 can recognizethat the user has entered in an office environment based at least partlyon the presence of one or more physical objects in the environment.

Because the wearable system 200 detects that a change in environment hasoccurred (e.g., because the user walked from the break room 1240 b tothe office 1240 a), the wearable system 200 determines a settingassociated with muting content for the new environment. For example, thewearable system 200 can check whether a content blocking settingassociated with office 1240 a was previously enabled. If a contentblocking setting associated with office 1705 was previously enabled, thewearable system 200 can automatically apply the associated setting forthe content blocking. As an example, the content blocking setting forthe office 1240 a can include blocking entertainment content. Thus, asshown in FIG. 12D, the user can no longer perceive virtual gameapplications. The wearable system can also remove the crosswordapplication 1178 a (which the user was able to perceive in the breakroom 1240 b) and instead shows an office tools application 1252. Asanother example, the wearable system can update the contact list 1254 ofthe telepresence session to present work related contacts (rather thanthe user's friends outside of work). The wearable system can also sortthe contact list such that the work related contacts are more easilyperceived by the user (e.g., moving work related contacts to the top ofthe contact list) when the user is in the office 1240 a.

Although in this example, the user walks from the break room 1240 b tothe office 1240 a, similar techniques can also be applied if the userwalks from the office 1240 a to the break room 1240 b. In certainimplementations, although a user moves from one location to another, thewearable system may nevertheless apply the same setting for mutingvirtual content because the scene has not changed. For example, a usermay move from a park to a subway station. The wearable system can applythe same setting for muting virtual content because the park and thesubway station may both be considered as a public scene.

Computer Vision and Sensor Based Detection of Triggering Events

A triggering event can be detected using a variety of techniques. Atriggering event may be determined based on reactions of the user. Forexample, the wearable system can analyze data acquired by theinward-facing imaging system or by a physiological sensor. The wearablesystem can use the data to determine the user's emotional state. Thewearable system can detect the presence of a triggering event bydetermining whether the user is in a certain emotional state (such asangry, scared, uncomfortable, etc.). As an example, the wearable systemcan analyze the user's pupil dilation, heart rate, respiration rate, orperspiration rate to determine the user's emotional state.

The triggering event can also be detected using computer visiontechniques. For example, the wearable system can analyze the imagesacquired by the outward-facing imaging system to perform scenereconstruction, event detection, video tracking, object recognition,object pose estimation, learning, indexing, motion estimation, or imagerestoration, etc. One or more computer vision algorithms may be used toperform these tasks. Non-limiting examples of computer vision algorithmsinclude: Scale-invariant feature transform (SIFT), speeded up robustfeatures (SURF), oriented FAST and rotated BRIEF (ORB), binary robustinvariant scalable keypoints (BRISK), fast retina keypoint (FREAK),Viola-Jones algorithm, Eigenfaces approach, Lucas-Kanade algorithm,Horn-Schunk algorithm, Mean-shift algorithm, visual simultaneouslocation and mapping (vSLAM) techniques, a sequential Bayesian estimator(e.g., Kalman filter, extended Kalman filter, etc.), bundle adjustment,Adaptive thresholding (and other thresholding techniques), IterativeClosest Point (ICP), Semi Global Matching (SGM), Semi Global BlockMatching (SGBM), Feature Point Histograms, various machine learningalgorithms (such as e.g., support vector machine, k-nearest neighborsalgorithm, Naive Bayes, neural network (including convolutional or deepneural networks), or other supervised/unsupervised models, etc.), and soforth. As described with reference to FIG. 7 , one or more of thecomputer vision algorithms may be implemented by an object recognizer708 for recognizing objects, events, or environments.

One or more of these computer vision techniques can also be usedtogether with data acquired from other environmental sensors (such as,e.g., microphone) to detect the presence of the triggering event.

The triggering event may be detected based on one or more criteria.These criteria may be defined by a user. For example, the user may set atriggering event to be fire in the user's environment. Therefore, whenthe wearable system detects the fire using a computer vision algorithmor using data received from a smoke detector (which may or may not bepart of the wearable system), the wearable system can then signal thepresence of the triggering event and automatically mute the virtualcontent being displayed. The criteria may also be set by another person.For example, the programmer of the wearable system may set a triggeringevent to be overheating of the wearable system.

The presence of the triggering event may also be indicated by a user'sinteractions. For example, the user may make a certain pose (e.g., ahand gesture or a body pose) or actuate a user input device indicatingthe presence of the triggering event.

Additionally or alternatively, the criteria may also be learned based onthe user's behaviors (or behaviors of a group of users). For example,the wearable system can monitor when a user turns off the HMD. Thewearable system can observe that the user often turns of the wearablesystem in response to a certain type of virtual content (e.g., certaintypes of scenes in a movie). The wearable system may accordingly learnthe user's behavior and predict a triggering event based on the user'sbehavior. As another example, the wearable system can associate theuser's emotional state based on the user's previous interactions withvirtual content. The wearable system can use this association to predictwhether a triggering event is present when the user is interacting witha virtual object.

The triggering event may also be based on known objects. For example,the wearable system may block virtual content from the display in agiven location. The wearable system can automatically block othervirtual content having similar characteristics at the given location.For example, a user may configure blocking a video watching applicationin a car. Based on this configuration, the wearable system canautomatically block a movie and a music application even though the userdid not specifically configure blocking of the movie and the musicapplication, because the movie and music application share similarcharacteristics as the video watching application (e.g., all of them areaudiovisual entertainment content).

Machine Learning of Triggering Events

A variety of machine learning algorithms can be used to learn triggeringevents. Once trained, a machine learning model can be stored by thewearable system for subsequent applications. As described with referenceto FIG. 7 , one or more of the machine learning algorithms or models maybe implemented by the object recognizer 708.

Some examples of machine learning algorithms can include supervised ornon-supervised machine learning algorithms, including regressionalgorithms (such as, for example, Ordinary Least Squares Regression),instance-based algorithms (such as, for example, Learning VectorQuantization), decision tree algorithms (such as, for example,classification and regression trees), Bayesian algorithms (such as, forexample, Naive Bayes), clustering algorithms (such as, for example,k-means clustering), association rule learning algorithms (such as, forexample, a-priori algorithms), artificial neural network algorithms(such as, for example, Perceptron), deep learning algorithms (such as,for example, Deep Boltzmann Machine, or deep neural network),dimensionality reduction algorithms (such as, for example, PrincipalComponent Analysis), ensemble algorithms (such as, for example, StackedGeneralization), and/or other machine learning algorithms. In someembodiments, individual models can be customized for individual datasets. For example, the wearable device can generate or store a basemodel. The base model may be used as a starting point to generateadditional models specific to a data type (e.g., a particular user), adata set (e.g., a set of additional images obtained), conditionalsituations, or other variations. In some embodiments, the wearablesystem can be configured to utilize a plurality of techniques togenerate models for analysis of the aggregated data. Other techniquesmay include using pre-defined thresholds or data values.

The criteria can include a threshold condition. If the analysis of thedata acquired by the environmental sensor indicates that the thresholdcondition is passed, the wearable system may detect the presence of thetriggering event. The threshold condition may involve a quantitativeand/or qualitative measure. For example, the threshold condition caninclude a score or a percentage associated with the likelihood of thetriggering event is occurring. The wearable system can compare the scorecalculated from the environmental sensor's data with the thresholdscore. If the score is higher than the threshold level, the wearablesystem may detect the presence of the triggering event. In otherembodiments, the wearable system can signal the presence of thetriggering event if the score is lower than the threshold.

The threshold condition may also include letter grades such as such as“A”, “B”, “C”, “D”, and so on. Each grade may represent a severity ofthe situation. For example, “A” may be the most severe while “D” may beleast severe. When the wearable system determines that an event in theuser's environment is severe enough (as compared to the thresholdcondition), wearable system may indicate the presence of a triggeringevent and take action (e.g., muting the virtual content).

The threshold condition may be determined based on objects (or people)in the user's physical environment. For example, a threshold conditionmay be determined based on the user's heart rate. If the user's heartrate exceeds a threshold number (e.g., a certain number of beats perminute), the wearable system may signal the presence of the triggeringevent. As another example described above with reference to FIGS. 11Aand 11B, the user of the wearable system may be a surgeon performing asurgery on a patient. The threshold condition may be based on thepatient's blood loss, the patient's heart rate, or other physiologicalparameters. As described with reference to FIGS. 2 and 10 , the wearablesystem can acquire the data of the patient from the environmentalsensors (e.g., an outward-facing camera that images the surgical site)or from an external source (such as, e.g., ECG data monitored by anelectrocardiograph). As yet another example, the threshold condition maybe determined based on the presence of certain objects (such as thepresence of fire or smoke) in the user's environment.

The threshold condition may also be determined based on the virtualobjects being displayed to the user. As one example, the thresholdcondition may be based on the presence of certain number of virtualobjects (such as e.g., a number of missed virtual telepresence callsfrom a person). As another example, the threshold condition may be basedon the user's interaction with the virtual object. For example, thethreshold condition may be the duration of the user watching a piece ofvirtual content.

In some embodiments, the threshold conditions, the machine learningalgorithms, or the computer vision algorithms may be specialized for aspecific context. For example, in a surgical context, the computervision algorithm may be specialized to detect certain surgical events.As another example, the wearable system may execute facial recognitionalgorithms (rather than event tracing algorithms) in the educationalcontext to detect whether a person is near the user.

Example Alerts

The wearable system can provide to the user an indication of thepresence of the triggering event. The indication may be in the form of afocus indicator. The focus indicator can comprise a halo, a color, aperceived size or depth change (e.g., causing a virtual object to appearcloser and/or larger when selected), a change in a user interfaceelement (e.g., changing the shape of a cursor from a circle to anescalation mark), a message (with text or graphics), or other audible,tactile, or visual effects which draw the user's attention. The wearablesystem may present the focus indicator near the cause of the triggeringevent. For example, a user of the wearable system may be cooking on astove and watching a virtual TV show with the wearable system. However,the user may forget about the food he is cooking while watching the TVshow. As a result, the food may be burnt, thereby producing smoke orflames. The wearable system can detect smoke or flames usingenvironmental sensors or by analyzing images of the stove. The wearablesystem can further detect that the source of the smoke or flames is thefood on the stove. Accordingly, the wearable system may present a haloaround the food on the stove indicating that it is burning. Thisimplementation may be beneficial because the user may be able to curethe source of the triggering event (e.g., by turning off the stove)before the event escalates (e.g., into a house fire). While thetriggering event is occurring, the wearable system may automaticallymute the display of virtual content that is not associated with thetriggering event (such as, e.g., the virtual TV show) so that the usercan focus attention on the triggering event. Continuing with the aboveburnt food example, the wearable system may mute virtual content notassociated with the food or stove, while emphasizing the source of thetriggering event (e.g., by continuing to display a halo around the burntfood).

As another example, the focus indicator may be an alert message. Forexample, the alert message may include a brief description of thetriggering event (such as, e.g., fire on the second floor, patient'sblood loss exceeds a certain number, etc.). In some embodiments, thealert message may also include one or more recommendations to cure thetriggering event. For example, the alert message may say, call fireman,infuse a certain type of blood, etc.

In certain implementations, the wearable system can use a user'sresponse to the alert message to update the wearable system'srecognition of a triggering event. For example, a wearable system canrecognize, based on images acquired by the outward-facing imagingsystem, that a user has arrived at home. Thus, the wearable system maypresent the virtual content tailored to the user's home. But the user isactually at a friend's house. The user can provide an indication, e.g.,by actuating the reality button, using hand gestures, or actuating auser input device, to dismiss the virtual content or change in setting.The wearable system can remember the user's response for thisenvironment, and will not present the virtual content tailored to theuser's home next time when the user is at the same house.

As another example, the wearable system can recognize an emergencysituation and present a message for automatically shutting off thedisplay. The user can also provide indication to prevent the wearablesystem from shutting off the display. The wearable system can rememberthe user's response, and use this response for updating a model used byan object recognizer 708 for determining the presence of the emergencysituation.

Examples of Muting Components of a Wearable System or Virtual Content inResponse to a Triggering Event

In response to a triggering event the wearable system can mute visualaudible virtual content. For example, the wearable system canautomatically mute the audio from the HMD, turn off the virtual contentdisplayed by the HMD, cause the HMD to enter a sleep mode, dim the lightfield of the HMD, reduce the amount of virtual content (e.g., by hidingvirtual content, moving virtual content out of the FOV, or reducing thesize of a virtual object). In embodiments in which the wearable systemprovides tactile virtual content (e.g., vibrations), the wearable systemcan additionally or alternatively mute the tactile virtual content. Inaddition to or in alternative to muting audio or visual content, thewearable system can also mute one or more of other components of thewearable system. For example, the wearable system can selectivelysuspend the outward-facing imaging system, the inward-facing imagingsystem, the microphone, or other sensitive sensors of the wearablesystem. For example, the wearable system may include two eye camerasconfigured to image the user's eyes. The wearable system may mute one orboth eye cameras in response to the triggering event. As anotherexample, the wearable system may turn off one or more cameras configuredto image the user's surroundings in the outward-facing imaging system.In some embodiments, the wearable system may change one or more camerasin the inward-facing imaging system or the outward-facing imaging systemto low resolution mode such that the images acquired may not have finedetails. These implementations may reduce the wearable system's batteryconsumption when the user is not viewing the virtual content.

Continuing with the example user environment shown in FIGS. 12A-12C,FIG. 12B illustrates an example FOV where the virtual display of thewearable system has been turned off. In this figure, the user canperceive only physical objects 1210, 1212, 1214, and 1216 in his FOV1200 b because the virtual display of the wearable system has turnedoff. This figure is in contrast with FIG. 12A where the wearable systemis turned on. In FIG. 12A, the user can perceive virtual objects 1222,1224 in the FOV 1200 a while in FIG. 12B, the user is not able toperceive the virtual objects 1222, 1224.

Advantageously, in some embodiments, the wearable system can allowfaster re-start or resume after a triggering event by keeping the restof the wearable system components continuously operating while mutingthe presentation of the virtual content in response to the triggeringevent. For example, the wearable system may mute (or completely turnoff) the speaker or the display, while keeping the rest of the wearablesystem components in a functioning state. Accordingly, after thetriggering event has ceased, the wearable system may not need to restartall components as comparing to a full restart when the wearable systemis completely turned off. As one example, the wearable system can mutethe display of virtual images but leave the audio on. In this example,wearable system can reduce visual confusion in response to a triggeringevent while allow the user to hear an alert via the speaker of thewearable system. As another example, a triggering event can occur whenthe user is in a telepresence session. The wearable system can mute thevirtual content as well as the sound associated with the telepresencesession but allow the telepresence application running in the backgroundof the wearable system. As yet another example, the wearable system canmute the virtual content (and the audio) while keep one or moreenvironmental sensors operating. In response to the triggering event,the wearable system can turn off the display while continuously acquiredata use GPS sensor (for example). In this example, the wearable systemcan allow a rescuer to more accurately locate the position of the userin an emergency situation.

FIG. 12C illustrates an example FOV where the wearable system hasreduced the amount of virtual content. Comparing to FIG. 12A, thevirtual avatar 1224 in FOV 1200 c has been reduced in size. In addition,the wearable system has moved the virtual avatar 1224 from close to thecenter of the FOV to the bottom right corner. As a result, the virtualavatar 1224 is deemphasized and may create less perceptual confusion forthe user. In addition, the wearable system has moved the virtualbuilding 1222 to the outside of the FOV 1200 c. As a result, the virtualobject 1224 does not appear in the FOV 1200 c.

In addition to or as an alternative to automatically muting virtualcontent based on a triggering event, the wearable system can also mutethe virtual content when a user manually actuates a reality button(e.g., the reality button 263 in FIG. 2 ). For example, the user canpress the reality button to turn off audio or visual content or gentlytap the reality button to move the virtual content out of the FOV.Further details relating to the reality button are described below withreference to FIGS. 14A and 14B.

In some embodiments, upon detecting a triggering event, the wearablesystem may present an audible, tactile, or visual indication of thetriggering event to the user. If the user does not respond to thetriggering event, the wearable system may automatically be muted toreduce the perceptual confusions. In other embodiments, the wearablesystem will be muted if the user responds to the indication of thetriggering event. For example, the user may respond by actuating arealty button or a user input device, or by providing a certain pose(such as e.g., waiving his hand in front of the outward-facing imagingsystem).

Example Processes for Muting a Wearable Device

FIGS. 13A and 13B illustrate example processes of muting the wearablesystem based on a triggering event. The processes 1310 and 1320 in FIGS.13A and 13B (respectively) may be performed by the wearable systemdescribed herein. In these two processes, one or more blocks may beoptional or be part of another block. In addition, these two processesare not required to be performed in the sequence indicated by the arrowsin the figures.

At block 1312 of the process 1310, the wearable system can receive datafrom environmental sensors. The environmental sensors may include usersensors as well as external sensors. Accordingly, the data acquired bythe environment sensors can include data associated with the user andthe user's physical environment. In some embodiments, the wearablesystem can communicate with another data source to acquire additionaldata. For example, the wearable system can communicate with a medicaldevice to obtain a patient's data (such as heart rate, respiratory rate,disease history, etc.). As another example, the wearable system cancommunicate with a remote data store to determine the information ofvirtual objects (such as e.g., the type of movie the user is watching,the previous interactions of the virtual objects, etc.) for which theuser is currently interacting. In some implementations, the wearablesystem can receive the data from an external imaging system incommunication with the wearable system or from an internal imagingsystem that is networked to external imaging systems.

At block 1314, the wearable system analyzes the data to detect atriggering event. The wearable system may analyze the data in view of athreshold condition. If the data indicates that the threshold conditionis passed, the wearable system can detect the presence of a triggeringevent. The triggering event may be detected in real-time using computervision algorithms. The triggering event may also be detected based onone or more predictive models. For example, wearable system may indicatethe presence of a triggering event if the likelihood of the triggeringevent occurring exceeds a threshold condition.

At block 1316, the display system can automatically be muted in responseto the triggering event. For example, the wearable system canautomatically turn off the virtual content display or mute a portion ofthe virtual content presented by the display. As a result, the user maysee through the wearable system into the physical environment withoutdistractions by the virtual content or without problems fordistinguishing a real physical object from a virtual object, or mayperceive virtual content relevant to a certain environment. As anotherexample, the wearable system can turn off the sound or lower the volumeof the sound associated with the virtual content to reduce perceptualconfusions.

At optional block 1318 a, the wearable system can determine thetermination of a triggering event. For example, the wearable system candetermine whether the situation which caused the triggering event isover (e.g., the fire is put out) or the user is no longer in the sameenvironment (e.g., a user walks from home to a park). If the triggeringevent is no longer present, the process 1310 may proceed to optionalblock 1318 b to resume the display system or the muted virtual content.

In some situations, the wearable system can determine, at the optionalblock 1318 b, the presence of a second triggering event. The secondtriggering event may cause the wearable system to resume the displaysystem or a portion of the muted virtual content, or cause the wearablesystem to mute other virtual content, the display system or othercomponents of the wearable system (if they were not previously muted).

The process 1320 in FIG. 13B illustrates another example process ofmuting virtual content based on a triggering event. The blocks 1312 and1314 in the processes 1310 and 1320 follow the same description.

At block 1322, the wearable system can determine whether the triggeringevent is present based on the analysis of data at block 1314. If thetriggering event is not present, the process 1320 goes back to the block1312 where the wearable system continuously monitors data acquired fromthe environmental sensors.

If the triggering event is detected, at block 1324, the wearable systemcan provide an indication of the triggering event. As described withreference to FIG. 12A, the indication may be a focus indicator. Forexample, the indication may be an alert message. The alert message maystate that a triggering event has been detected and if no response isreceived from the user for a certain period of time (e.g., 5 seconds, 30seconds, 1 minute, etc.), the wearable system may automatically mute theperceptual confusions.

At block 1324, the wearable system can determine whether a response tothe indication has been received. The user can respond to the indicationby actuating a user input device or a reality button. The user can alsorespond by a change in pose. The wearable system can determine whetherthe user has provided the response by monitoring the input from the userinput device or the reality button. The wearable system can also analyzethe images acquired by the outward-facing imaging system or dataacquired by the IMUs to determine whether the user has changed his poseto provide the response.

If the wearable system does not receive the response, the wearablesystem may automatically mute virtual content (or the sound) at block1328. If the wearable system does receive the response, the process 1320ends. In some embodiments, the wearable system may continuously monitorthe environmental sensor if the wearable system receives the response.The wearable system may later detect another triggering event. In someembodiments, the response received from the user instructs the wearablesystem to perform another action not provided in the indication. As anexample, the wearable system may provide an alert message indicatingthat the virtual display will be turned off in the user does not respondwithin a threshold time duration. However, the user does respond withinthe time duration, for example, by tapping twice on the reality button.But this response is associated with dimming the light field (instead ofturning off). Accordingly, the wearable system may instead dim the lightfield instead of turning it off as indicated in the alert message.

The process 1330 in FIG. 13C illustrates an example of selectivelyblocking virtual content according to an environment. The process 1330can be performed by the wearable system 200 described herein.

The process 1330 starts from block 1332 and moves to block 1334. Atblock 1334, the wearable system can receive data acquired from anenvironmental sensor of a wearable device. For example, the wearablesystem can receive images acquired by the outward-facing imaging system464 of the wearable device. In some implementations, the wearable systemcan receive the data from an external imaging system in communicationwith the wearable system or from an internal imaging system that isnetworked to external imaging systems.

At block 1336, the wearable system analyzes data gathered and receivedby the environmental sensor. Based at least partly on the data receivedfrom the environmental sensor, the wearable system will recognize theenvironment in which the user of the wearable system is currentlysituated. As described with reference to FIG. 11F, the wearable systemmay recognize the environment based on the presence of physical objectsin the environment, the arrangement of physical objects in theenvironment, or the user's location in relation to physical objects inthe environment.

At block 1338, the wearable system checks the content blocking settingfor the environment. For example, the wearable system can determinewhether the user has entered into a new environment (e.g., whether theuser has entered a leisure environment from a work environment). If thewearable system determines that the user has not entered into a newenvironment, the wearable system can apply the same setting as theprevious environment, and thus the blocks 1340-1352 may become optional.

At block 1340, the wearable system determines whether it has received anindication to enable or to edit a content blocking setting. Suchindication may come from a user (such as, e.g., based on the user's poseor inputs from a user input device). The indication may also beautomatic. For example, the wearable system can automatically apply asetting specific to an environment in response to a triggering event.

If the wearable system does not receive the indication, the process 1330moves to the block 1350 where the wearable system determines whether acontent blocking setting has previously been enabled. If not, at block1352, the virtual content is presented without blocking. Otherwise, atblock 1344, the wearable system can selectively block the virtualcontent based on the content blocking setting.

If the wearable system receives the indication, the wearable system canedit a content blocking setting or create a new content blockingsetting. Where the setting needs to be configured for a new environment,the wearable system can initiate storage of the content blocking settingat block 1342. Accordingly, when the user enters into the same oranalogous new environment again, the wearable system can automaticallyapply the content blocking setting. Further, if the user can reconfigurethe existing content blocking setting which will be stored and later beapplied to the same or similar environment.

The content blocking setting associated with the environment may residelocally on the wearable device (e.g., at the local processing and datamodule 260) or remotely at networked storage locations (e.g., the remotedata repository 280) accessible by a wired or wireless network. In someembodiments, the content blocking setting may partly reside locally onthe wearable system, and may partly reside at networked storagelocations accessible by wired or wireless network.

At block 1344, the wearable system implements the stored contentblocking setting associated with the new environment. By applying thecontent blocking setting associated with the new environment, some orall virtual content will be blocked according to the content blockingsetting. The process then loops back to block 1332.

At block 1350, the wearable system can check whether the contentblocking setting was previously enabled 1350. If not, the wearablesystem can present the virtual content without blocking at block 1352.Otherwise, the wearable system can selectively block virtual contentbased on the content blocking setting at block 1344. The blocks1350-1352 and the blocks 1340-1344 may be run in parallel or insequence. For example, the wearable system can check whether there is aprevious content blocking setting while determining whether it hasreceived an indication to modify a content blocking setting for theenvironment.

Manual Control of a Wearable Display System

As described herein, embodiments of the wearable display system mayautomatically control visual or audible display of virtual content basedon the occurrence of a triggering event in the user's environment.Additionally or alternatively, the user may desire to have the abilityto manually mute the visual or audible virtual content.

Accordingly, as described with reference to FIG. 2 , the display system100 can include a user-selectable reality button 263. The reality button263 can mute the wearable device's visual display 220 or audio system(e.g., the speaker 240) in response to certain situations, such as,e.g., unexpected loud noises, unpleasant or unsafe experiences orconditions in the physical or virtual environment, emergencies in thereal world, or simply because the user desires to experience more“actual” reality than augmented or mixed reality (e.g., to talk tofriend without the display of virtual content).

The reality button 263 (once actuated) can cause the display system 100to turn off or dim the brightness of the display 220 or audibly mute theaudio from the speakers 240. As a result, the user 210 will be able toperceive the physical objects in the environment more easily, becauseperceptual confusion caused by the display of virtual objects or soundto the user will be reduced or eliminated. In some embodiments, when thereality button 263 is actuated, the display system 100 may turn off theVR or AR display 220 and the speaker 600 while the rest of the displaysystem 100 (such as the environmental sensors, the user input device,etc.) may continue to operate normally (which may provide for fasterre-start after the wearable device is unmuted).

The reality button 263 can cause the display system 100 to reduce theamount of virtual content. For example, the display system 100 to reducethe size of the virtual objects in the FOV (e.g., reduce the size of avirtual avatar or another virtual object), make the virtual objects moretransparent, or reduce the brightness at which the virtual objects aredisplayed. The reality button 263 can additionally or alternativelycause the display system 100 to move the virtual content from onelocation to the other, such as by moving a virtual object from insidethe FOV to outside of the FOV or moving the virtual object from acentral region to a peripheral region. Additionally or alternatively,the reality button 263 can dim the light field generated by the displaysystem, therefore reducing the likelihood of perceptual confusion. Incertain implementations, the display system 100 can mute only a portionof the virtual content when the reality button 263 is actuated. Forexample, while a user of the wearable device is shopping in a store, thewearable device may display virtual content such as the price of theclothes in the store as well as the map of the department store. Inresponse to a loud noise in the department store, upon actuation of thereality button 263, the wearable device may hide or move the virtualcontent (e.g., to the outside of the FOV) related to the price of theclothes but nevertheless leaves the map on in case the user needs toleave the store quickly.

The reality button 263 may be a touch-sensitive sensor that is mountedto the frame 230 of the display system 100 or on a battery pack thatprovides electrical power to the display system 100. The user may wearthe battery pack, for example, on his waist. The reality button 263 maybe a touch sensitive region which the user can actuate, for example, bya touch gesture or by swiping along a trajectory. For example, byswiping downward on the touch-sensitive portion, the wearable device maybe muted, whereas by swiping upward, the wearable device may be restoredto its normal functioning.

In some embodiments, the wearable device may (additionally oralternatively) include a virtual reality button, which is not a physicalbutton, but rather functionality that is actuated by a user gesture. Forexample, the outward-facing cameras of the wearable device may image theuser's gestures and if a particular “mute” gesture is recognized (e.g.,the user holding up his hand and forming a fist), then the wearabledevice will mute the visual or audible content being displayed to theuser. In some embodiments, after actuation of the reality button 263 bythe user, the display system 100 may display an alert message 1430(shown in FIG. 14A), which notifies the user that the display will bemuted. In some embodiments, the display system 100 will be muted after atime period passes (e.g., 5 seconds, as shown in FIG. 14A) unless theuser actuates the reality button 263 a second time or actuates thevirtual alert message 1430 (or a virtual button associated with themessage 1430) to cancel the muting. In other embodiments, the realitybutton 263 must be actuated a second time or the virtual alert message1430 (or a virtual button associated with the message 1430) must beactuated before the display system 100 mutes the visual or audibledisplay. Such functionality can be beneficial in situations where theuser inadvertently actuates the reality button 263 but does not want thedisplay system 100 to enter a mute mode.

After the mute mode has been entered, the user may revert to normaloperations by actuating the reality button 263, accessing a userinterface to restore normal operations, speaking a command, or allowinga period of time to pass.

FIG. 14B is a flowchart that shows an example process 1400 for manuallyactivating a mute mode of operation of the display system 100. Theprocess 1400 can be performed by the display system 100. At block 1404,the process receives an indication that the reality button has beenactuated. At optional block 1408, the process causes the display systemto display an alert message indicating to the user that the displaysystem will enter a mute mode of operation. In the mute mode ofoperation, the visual or audible display of virtual content may beattenuated. At optional decision block 1410, the process determineswhether the user has provided an indication that the mute mode ofoperation should be canceled (e.g., by the user actuating the realitybutton a second time or actuating the alert message). If a cancellationis received, the process ends. If the cancellation is not received, thedisplay system is visually or audibly muted, in some implementations,after a time period (e.g., 3 s, 5 s, 10 s, etc.). Although the exampleprocess 1400 describes receiving a cancellation request at block 1410,in other embodiments the process 1400 may determine whether aconfirmation is received at block 1410. If the confirmation is received,the process 1400 moves to block 1412 and mutes the display system, andif the confirmation is not received, the process 1400 ends.

Additional Aspects

In a 1st aspect, a head-mounted device (HMD) configured to displayaugmented reality image content, the HMD comprising: a displayconfigured to present virtual content, at least a portion of the displaybeing transparent and disposed at a location in front of a user's eyewhen the user wears the HMD such that the transparent portion transmitslight from a portion of the environment in front of the user to theuser's eye to provide a view of the portion of the environment in frontof the user, the display further configured to display virtual contentto the user at a plurality of depth planes; an environmental sensorconfigured to acquire data associated with at least one of (1) anenvironment of the user or (2) the user; and a hardware processorprogrammed to: receive data from the environmental sensor; analyze thedata to detect a triggering event; in response to detection of thetriggering event, provide an indication of an occurrence of thetriggering event to the user; and mute the display of the HMD.

In a 2nd aspect, the HMD of aspect 1, wherein to mute the display of theHMD, the hardware processor is at least programmed to: dim light outputby the display; turn off display of the virtual content; reduce a sizeof the virtual content; increase a transparency of the virtual content;or change a position of the virtual content as rendered by the display.

In a 3rd aspect, the HMD of any one of aspects 1-2, wherein the HMDfurther comprises a speaker, and to mute the display of the HMD, thehardware processor is programmed to mute the speaker.

In a 4th aspect, the HMD of any one of aspects 1-3, wherein to analyzethe data to detect the triggering event, the hardware processor isprogrammed to: analyze the data in view of a threshold conditionassociated with a presence of the triggering event; detect the presenceof the triggering event if the threshold condition is passed.

In a 5th aspect, the HMD of any one of aspects 1-4, wherein the hardwareprocessor is programmed with at least one of a machine learningalgorithm or a computer vision algorithm to detect the triggering event.

In a 6th aspect, the HMD of any one of aspects 1-5, wherein theindication of the presence of the triggering event comprises a focusindicator associated with an element in the environment that is at leastpartly responsible for the triggering event.

In a 7th aspect, the HMD of any one of aspects 1-6, wherein theindication of the presence of the triggering event comprises an alertmessage, wherein the alert message indicates to the user at least oneof: (1) that the HMD will be automatically muted in a time period unlessthe user performs a cancellation action or (2) that the HMD will not bemuted unless the user performs a confirmation action.

In an 8th aspect, the HMD of aspect 7, wherein the cancellation actionor the confirmation action comprise at least one of: actuating a realitybutton, actuating a virtual user interface element rendered by thedisplay, actuating a user input device, or detecting a cancellation orconfirmation pose of the user.

In a 9th aspect, the HMD of any one of aspects 7-8, wherein in responseto the user performing the cancellation action, the hardware processoris programmed to unmute the display or continue displaying the virtualcontent.

In a 10th aspect, the HMD of any one of aspects 7-9, wherein in responseto the user performing the confirmation action, the hardware processoris programmed to mute the display or cease displaying the virtualcontent.

In an 11th aspect, the HMD of any one of aspects 1-10, wherein theenvironmental sensor comprises at least one of: a user sensor configuredto measure data associated with the user of the HMD or an externalsensor configured to measure data associated with the environment of theuser.

In a 12th aspect, the HMD of any one of aspects 1-11, wherein thetriggering event comprises an emergency or unsafe condition in theuser's environment.

In a 13th aspect, the HMD of any one of aspects 1-12, wherein thedisplay comprises a light field display.

In a 14th aspect, the HMD of any one of aspects 1-13, wherein thedisplay comprises: a plurality of waveguides; one or more light sourcesconfigured to direct light into the plurality of waveguides.

In a 15th aspect, the HMD of aspect 14, wherein the one or more lightsources comprise a fiber scanning projector.

In a 16th aspect, the HMD of any one of aspects 1-15, wherein theenvironmental sensor comprises an outward-facing imaging system to imagethe environment of the user; the data comprises images of theenvironment acquired by the outward-facing imaging system; and toanalyze the data to detect a triggering event, the hardware processor isprogrammed to analyzes images of the environment of the environment viaone or more of: a neural network or a computer vision algorithm.

In a 17th aspect, the HMD of aspect 16, wherein the neural networkcomprises a deep neural network or a convolutional neural network.

In an 18th aspect, the HMD of any one of aspects 16-18, wherein thecomputer vision algorithm comprises one or more of: a Scale-invariantfeature transform (SIFT), a speeded up robust features (SURF), orientedFAST and rotated BRIEF (ORB), a binary robust invariant scalablekeypoints (BRISK) algorithm, a fast retina keypoint (FREAK) algorithm, aViola-Jones algorithm, an Eigenfaces algorithm, a Lucas-Kanadealgorithm, a Horn-Schunk algorithm, a Mean-shift algorithm, a visualsimultaneous location and mapping (vSLAM) algorithm, a sequentialBayesian estimator, a Kalman filter, a bundle adjustment algorithm, anAdaptive thresholding algorithm, an Iterative Closest Point (ICP)algorithm, a Semi Global Matching (SGM) algorithm, a Semi Global BlockMatching (SGBM) algorithm, a Feature Point Histogram algorithm, asupport vector machine, a k-nearest neighbors algorithm, or a Bayesmodel.

In a 19th aspect, the HMD of any one of aspects 1-18, wherein theenvironmental sensor comprises an outward-facing imaging system to imagethe environment of the user; the data comprises images of theenvironment acquired by the outward-facing imaging system; and toanalyze the data to detect a triggering event, the hardware processor isprogrammed to: access a first image of the environment; access a secondimage of the environment, the second image acquired by theoutward-facing imaging system after the first image; compare the secondimage with the first image to determine occurrence of the triggeringevent.

In a 20th aspect, the HMD of any one of aspects 1-19, wherein theenvironmental sensor comprises an outward-facing imaging system to imagethe environment of the user, the environment comprising a surgical site;the data comprises images of the surgical site acquired by theoutward-facing imaging system; and to analyze the data to detect atriggering event, the hardware processor is programmed to: monitor amedical condition occurring in the surgical site; detect a change in themedical condition; determine that the change in the medical conditionpasses a threshold.

In a 21st aspect, an HMD configured to display augmented reality imagecontent, the HMD comprising: a display configured to present virtualcontent, at least a portion of the display being transparent anddisposed at a location in front of a user's eye when the user wears theHMD such that the transparent portion transmits light from a portion ofthe environment in front of the user to the user's eye to provide a viewof the portion of the environment in front of the user, the displayfurther configured to display virtual content to the user at a pluralityof depth planes; a user-actuatable button; and a hardware processorprogrammed to: receive an indication that the user-actuatable button hasbeen actuated; and in response to the indication, mute the display ofthe HMD.

In a 22nd aspect, the HMD of aspect 21, wherein to mute the display ofthe HMD, the hardware processor is at least programmed to: dim lightoutput by the display; turn off display of the virtual content; reduce asize of the virtual content; increase a transparency of the virtualcontent; or change a position of the virtual content as rendered by thedisplay.

In a 23rd aspect, the HMD of aspect 21 or aspect 22, wherein the HMDfurther comprises a speaker, and to mute the display of the HMD, thehardware processor is programmed to mute the speaker.

In a 24th aspect, the HMD of any one of aspects 21-23, wherein inresponse to the indication, the hardware processor is programmed toprovide an alert to the user.

In a 25th aspect, the HMD of aspect 24, wherein the alert comprises ofvisual alert rendered by the display or an audible alert provided by aspeaker.

In a 26th aspect, the HMD of any one of aspects 24-25, wherein the alertindicates to the user at least one of: (1) that the HMD will beautomatically muted in a time period unless the user performs acancellation action or (2) that the HMD will not be muted unless theuser performs a confirmation action.

In a 27th aspect, the HMD of aspect 26, wherein the cancellation actionor the confirmation action comprise at least one of: actuating theuser-actuatable button, actuating a virtual user interface elementrendered by the display, actuating a user input device, or detecting acancellation or confirmation pose of the user.

In a 28th aspect, the HMD of any one of aspects 26-27, wherein inresponse to the user performing the cancellation action, the hardwareprocessor is programmed to unmute the display or continue displaying thevirtual content.

In a 29th aspect, the HMD of any one of aspects 26-28, wherein inresponse to the user performing the confirmation action, the hardwareprocessor is programmed to mute the display or cease displaying thevirtual content.

In a 30th aspect, the HMD of any one of aspects 21-29, wherein thehardware processor is further programmed to: receive a second indicationthat the user-actuatable button has been actuated; and in response tothe second indication, unmute the display of the HMD.

In a 31st aspect, a wearable system configured to display virtualcontent in a mixed reality or virtual reality environment, the wearablesystem comprising: a display configured to present virtual content in amixed reality, augmented reality, or virtual reality environment; and ahardware processor programmed to: receive an image of the user'senvironment; analyze the image using one or more object recognizersconfigured to recognize objects in the environment with machine learningalgorithms; detect a triggering event based at least partly on ananalysis of the image; in response to a detection of the triggeringevent: mute the display in response to a determination that a thresholdcondition associated with the triggering event is met.

In a 32nd aspect, the wearable system of aspect 31, wherein to mute thedisplay, the hardware processor is programmed to at least: dim lightoutput by the display; turn off the display of the virtual content;reduce a size of the virtual content; increase a transparency of thevirtual content; or change a position of the virtual content as renderedby the display.

In a 33rd aspect, the wearable system of any one of aspects 31-33,wherein the hardware processor is further programmed to: detect atermination condition of the triggering event; and resume the display inresponse to a detect a termination condition.

In a 34th aspect, the wearable system of aspect 33, wherein to detectthe termination condition, the wearable system is programmed to:determine whether the triggering event has terminated; or determinewhether the user has left the environment where the triggering eventoccurs.

In a 35th aspect, the wearable system of any one of aspects 31-34,wherein the hardware process is further programmed to mute a speaker ofthe wearable system in response to the detection of the triggeringevent.

In a 36th aspect, the wearable system of any one of aspect 31-35,wherein in response to the triggering event, the hardware processor isfurther programmed to provide an indication of a presence of thetriggering event, wherein the indication comprises at least one of: afocus indicator associated with an element in the environment that is atleast partly responsible for the triggering event; or an alert message,wherein the alert message indicates to the user at least one of: (1)that the HMD will be automatically muted in a time period unless theuser performs a cancellation action or (2) that the HMD will not bemuted unless the user performs a confirmation action.

In a 37th aspect, the wearable system of aspect 36, wherein thethreshold condition associated with the triggering event comprises aduration of time within which the cancellation action is not detected.

In a 38th aspect, the wearable system of aspect 36 or 37, wherein thecancellation action or the confirmation action comprise at least one of:actuating a reality button, actuating a virtual user interface elementrendered by the display, actuating a user input device, or detecting acancellation or confirmation pose of the user.

In a 39th aspect, the wearable system of any one of aspects 31-38,wherein the triggering event comprises an emergency or unsafe conditionin the user's environment.

In a 40th aspect, the wearable system of any one of aspects 31-39,wherein the machine learning algorithms comprises a deep neural networkor a convolutional neural network.

In a 41st aspect, a method for displaying virtual content in a mixedreality or virtual reality environment, the method comprising: receivingan image of a user's environment; analyzing the image using one or moreobject recognizers configured to recognize objects in the environment;detecting a triggering event based at least partly on an analysis of theimage; in response to a detection of the triggering event: mutingvirtual content in response to a determination that a thresholdcondition associated with the triggering event is met. The method can beperformed under control of a hardware processor. The hardware processormay be disposed in an augmented reality display device.

In a 42nd aspect, the method of aspect 41, wherein muting the virtualcontent comprises at least one of: blocking the virtual content frombeing rendered; disabling interactions with the virtual content; turningoff display of the virtual content; reducing a size of the virtualcontent; increasing a transparency of the virtual content; or changing aposition of the virtual content as rendered by the display.

In a 43rd aspect, the method of any one of aspects 41-42, furthercomprising: detecting a termination condition of the triggering event;and resuming the display in response to a detection of a terminationcondition.

In a 44th aspect, the method of aspect 43, wherein to detect thetermination condition, the wearable system is programmed to: determiningwhether the triggering event has terminated; or determining whether theuser has left the environment where the triggering event occurs.

In a 45th aspect, the method of any one of aspects 41-44, whereinanalyzing the image comprises recognizing objects in the user'senvironment; and determining the triggering event comprises determininga location of the user based at least partly on the recognized object.

In a 46th aspect, the method of aspect 45, wherein the triggering eventcomprises a change in the location of the user or a change in a scenesurrounding the user.

In a 47th aspect, the method of aspect 45 or 46, wherein in response tothe detection of the triggering event, the method further comprises:accessing a setting for muting the virtual content at the location, andmuting the virtual content in accordance with the setting.

In a 48th aspect, the method of any one of aspects 45-47, whereinrecognizing the objects in the user's environment is performed by aneutral network.

In a 49th aspect, the method of any one of aspects 41-48, wherein thethreshold condition associated with the triggering event comprises aduration of time within which a cancellation action is not detected.

In a 50th aspect, the method of any one of aspects 41-49, wherein thecancellation action comprises at least one of: actuating a realitybutton, actuating a virtual user interface element rendered by thedisplay, actuating a user input device, or detecting a cancellation orconfirmation pose of the user.

Other Considerations

Each of the processes, methods, and algorithms described herein and/ordepicted in the attached figures may be embodied in, and fully orpartially automated by, code modules executed by one or more physicalcomputing systems, hardware computer processors, application-specificcircuitry, and/or electronic hardware configured to execute specific andparticular computer instructions. For example, computing systems caninclude general purpose computers (e.g., servers) programmed withspecific computer instructions or special purpose computers, specialpurpose circuitry, and so forth. A code module may be compiled andlinked into an executable program, installed in a dynamic link library,or may be written in an interpreted programming language. In someimplementations, particular operations and methods may be performed bycircuitry that is specific to a given function.

Further, certain implementations of the functionality of the presentdisclosure are sufficiently mathematically, computationally, ortechnically complex that application-specific hardware or one or morephysical computing devices (utilizing appropriate specialized executableinstructions) may be necessary to perform the functionality, forexample, due to the volume or complexity of the calculations involved orto provide results substantially in real-time. For example, animationsor video may include many frames, with each frame having millions ofpixels, and specifically programmed computer hardware is necessary toprocess the video data to provide a desired image processing task orapplication in a commercially reasonable amount of time.

Code modules or any type of data may be stored on any type ofnon-transitory computer-readable medium, such as physical computerstorage including hard drives, solid state memory, random access memory(RAM), read only memory (ROM), optical disc, volatile or non-volatilestorage, combinations of the same and/or the like. The methods andmodules (or data) may also be transmitted as generated data signals(e.g., as part of a carrier wave or other analog or digital propagatedsignal) on a variety of computer-readable transmission mediums,including wireless-based and wired/cable-based mediums, and may take avariety of forms (e.g., as part of a single or multiplexed analogsignal, or as multiple discrete digital packets or frames). The resultsof the disclosed processes or process steps may be stored, persistentlyor otherwise, in any type of non-transitory, tangible computer storageor may be communicated via a computer-readable transmission medium.

Any processes, blocks, states, steps, or functionalities in flowdiagrams described herein and/or depicted in the attached figures shouldbe understood as potentially representing code modules, segments, orportions of code which include one or more executable instructions forimplementing specific functions (e.g., logical or arithmetical) or stepsin the process. The various processes, blocks, states, steps, orfunctionalities can be combined, rearranged, added to, deleted from,modified, or otherwise changed from the illustrative examples providedherein. In some embodiments, additional or different computing systemsor code modules may perform some or all of the functionalities describedherein. The methods and processes described herein are also not limitedto any particular sequence, and the blocks, steps, or states relatingthereto can be performed in other sequences that are appropriate, forexample, in serial, in parallel, or in some other manner. Tasks orevents may be added to or removed from the disclosed exampleembodiments. Moreover, the separation of various system components inthe implementations described herein is for illustrative purposes andshould not be understood as requiring such separation in allimplementations. It should be understood that the described programcomponents, methods, and systems can generally be integrated together ina single computer product or packaged into multiple computer products.Many implementation variations are possible.

The processes, methods, and systems may be implemented in a network (ordistributed) computing environment. Network environments includeenterprise-wide computer networks, intranets, local area networks (LAN),wide area networks (WAN), personal area networks (PAN), cloud computingnetworks, crowd-sourced computing networks, the Internet, and the WorldWide Web. The network may be a wired or a wireless network or any othertype of communication network.

The systems and methods of the disclosure each have several innovativeaspects, no single one of which is solely responsible or required forthe desirable attributes disclosed herein. The various features andprocesses described above may be used independently of one another, ormay be combined in various ways. All possible combinations andsubcombinations are intended to fall within the scope of thisdisclosure. Various modifications to the implementations described inthis disclosure may be readily apparent to those skilled in the art, andthe generic principles defined herein may be applied to otherimplementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein, but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Certain features that are described in this specification in the contextof separate implementations also can be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation also can be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination. No single feature orgroup of features is necessary or indispensable to each and everyembodiment.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include, whileother embodiments do not include, certain features, elements and/orsteps. Thus, such conditional language is not generally intended toimply that features, elements and/or steps are in any way required forone or more embodiments or that one or more embodiments necessarilyinclude logic for deciding, with or without author input or prompting,whether these features, elements and/or steps are included or are to beperformed in any particular embodiment. The terms “comprising,”“including,” “having,” and the like are synonymous and are usedinclusively, in an open-ended fashion, and do not exclude additionalelements, features, acts, operations, and so forth. Also, the term “or”is used in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list. In addition, thearticles “a,” “an,” and “the” as used in this application and theappended claims are to be construed to mean “one or more” or “at leastone” unless specified otherwise.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: A, B, or C” is intended to cover: A, B, C,A and B, A and C, B and C, and A, B, and C. Conjunctive language such asthe phrase “at least one of X, Y and Z,” unless specifically statedotherwise, is otherwise understood with the context as used in generalto convey that an item, term, etc. may be at least one of X, Y or Z.Thus, such conjunctive language is not generally intended to imply thatcertain embodiments require at least one of X, at least one of Y and atleast one of Z to each be present.

Similarly, while operations may be depicted in the drawings in aparticular order, it is to be recognized that such operations need notbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocesses in the form of a flowchart. However, other operations that arenot depicted can be incorporated in the example methods and processesthat are schematically illustrated. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the illustrated operations. Additionally, the operations may berearranged or reordered in other implementations. In certaincircumstances, multitasking and parallel processing may be advantageous.Moreover, the separation of various system components in theimplementations described above should not be understood as requiringsuch separation in all implementations, and it should be understood thatthe described program components and systems can generally be integratedtogether in a single software product or packaged into multiple softwareproducts. Additionally, other implementations are within the scope ofthe following claims. In some cases, the actions recited in the claimscan be performed in a different order and still achieve desirableresults.

What is claimed is:
 1. A wearable system configured to display virtual content in a mixed reality or virtual reality environment, the wearable system comprising: a display configured to present virtual content in a mixed reality, augmented reality, or virtual reality environment; and a hardware processor programmed to: receive images of an environment of a user; cause to be rendered by the display a plurality of virtual content items associated with the environment of the user; analyze the image using one or more object recognizers configured to recognize objects in the environment with machine learning algorithms; detect a triggering event based at least partly on an analysis of the image; and in response to a detection of the triggering event: access content blocking rules associated with the environment, wherein the content blocking rules comprise a blacklist indicating virtual content items that are available for muting; determine, based on the content blocking rules associated with the environment, one or more of the plurality of virtual content items that are available for muting in the environment; and mute the determined one or more virtual content.
 2. The wearable system of claim 1, wherein the content blocking rules are stored in a storage device in which, for each of a plurality of environments, a corresponding set of content blocking rules are stored.
 3. The wearable system of claim 1, wherein to mute the display, the hardware processor is programmed to at least: dim light output by the display; turn off the display of the virtual content; reduce a size of the virtual content; increase a transparency of the virtual content; or change a position of the virtual content as rendered by the display.
 4. The wearable system of claim 1, wherein the hardware processor is further programmed to: detect a termination condition of the triggering event; and discontinue muting the determined one or more virtual content items in response to a detect a termination condition.
 5. The wearable system of claim 4, wherein to detect the termination condition, the wearable system is programmed to: determine whether the triggering event has terminated; or determine whether the user has left the environment where the triggering event occurs.
 6. The wearable system of claim 1, wherein the hardware process is further programmed to mute a speaker of the wearable system in response to the detection of the triggering event.
 7. The wearable system of claim 1, wherein in response to the triggering event, the hardware processor is further programmed to provide an indication of a presence of the triggering event, wherein the indication comprises at least one of: a focus indicator associated with an element in the environment that is at least partly responsible for the triggering event; or an alert message, wherein the alert message indicates to the user at least one of: (1) that the wearable system will be automatically muted in a time period unless the user performs a cancellation action or (2) that the wearable system will not be muted unless the user performs a confirmation action.
 8. The wearable system of claim 7, wherein the processor is further programed to mute the determined one or more virtual content in response to a determination that a threshold condition associated with the triggering event is met, and wherein the threshold condition comprises a duration of time within which the cancellation action is not detected.
 9. The wearable system of claim 1, wherein the triggering event comprises an emergency or unsafe condition in the environment.
 10. The wearable system of claim 9, wherein the environment of the user comprises a surgical site and the emergency or unsafe condition comprises a medical condition occurring in the surgical site.
 11. The wearable system of claim 9, wherein the environment of the user is an industrial working site and the emergency or unsafe condition comprises a condition near the industrial working site.
 12. The wearable system of claim 1, wherein the wherein the environment of the user is an educational environment and the triggering event comprises a distance between the user from a student being less than a threshold distance.
 13. The wearable system of claim 9, wherein the environment of the user is a shopping environment and the emergency or unsafe condition comprises a distance of the user from a physical item being less than a threshold distance.
 14. The wearable system of claim 9, wherein the virtual content is a video game and the emergency or unsafe condition comprises a physiological condition of the user.
 15. The wearable system of claim 1, wherein virtual content items that are available for muting are further determined based on potential perceptual confusion to the user associated with the respective virtual content items.
 16. The wearable system of claim 1, wherein the blocking rules comprise a whitelist indicating virtual content items that are not available for muting.
 17. A method for displaying virtual content in a mixed reality or virtual reality environment, the method comprising: under control of a hardware processor: receiving an image of an environment of a user; analyzing the image using one or more object recognizers configured to recognize objects in the environment; detecting a triggering event based at least partly on an analysis of the image; and in response to a detection of the triggering event: accessing content blocking rules associated with the environment, wherein the content blocking rules comprise a blacklist indicating virtual content items that are available for muting; determining, based on the content blocking rules associated with the environment, one or more of the plurality of virtual content items that are available for muting in the environment; and muting the determined one or more virtual content items.
 18. The method of claim 17, wherein muting the virtual content comprises at least one of: blocking the virtual content from being rendered; disabling interactions with the virtual content; turning off display of the virtual content; reducing a size of the virtual content; increasing a transparency of the virtual content; or changing a position of the virtual content as rendered by the display.
 19. The method of claim 17, wherein analyzing the image comprises recognizing objects in the environment and determining the triggering event based at least partly on the recognized objects.
 20. The method of claim 19, wherein the determined one or more virtual content items include at least one virtual content item that is not associated with the recognized objects that are at least partly responsible for determining the triggering event. 